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105 results on '"Traianou, E."'

1. Investigating launching of black hole jets with the combined power of the EVN and the EHT

Author

Paraschos, G. F., Debbrecht, L. C., Kramer, J. A., Traianou, E., Liodakis, I., Krichbaum, T., Kim, J. -Y., Janssen, M., Nair, D. G., Savolainen, T., Ros, E., Bach, U, Hodgson, J. A., Lisakov, M., MacDonald, N. R., and Zensus, J. A.

Subjects
Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Astrophysics of Galaxies
Abstract

AGN-launched jets are a crucial element in the study of supermassive black holes (SMBH) and their closest surroundings. The formation of such jets, whether they are launched by magnetic field lines anchored to the accretion disc or directly connected to the black hole's (BH) ergosphere, is the subject of ongoing, extensive research. 3C84, the compact radio source in the central galaxy NGC1275 of the Perseus super-cluster, is a prime laboratory for testing such jet launching scenarios, as well as studying the innermost, sub-parsec AGN structure and jet origin. Very long baseline interferometry (VLBI) offers a unique view into the physical processes in action, in the immediate vicinity of BHs, unparalleled by other observational techniques. With VLBI at short wavelengths particular high angular resolutions are obtained. Utilising such cm and mm-VLBI observations of 3C84 with the European VLBI Network and the Event Horizon Telescope, we study the magnetic field strength and associated accretion flow around its central SMBH. This is possible, as higher frequency VLBI measurements are capable of peering through the accretion flow surrounding the central engine of 3C84, which is known to block the line of sight to the sub-parsec counter-jet via free-free absorption. Furthermore, we study the magnetic field's signature in the core region, as manifested in polarised light. As part of this analysis we compare our observations to relativistic magneto-hydrodynamic simulations. Finally, we investigate the effect of instabilities on the shape of the jet's parsec-scale funnel and try to connect them to its historical evolution., Comment: 4 pages, 4 figures, Proceedings of the 16th European VLBI Network Symposium

Published
2025

2. A wiggling filamentary jet at the origin of the blazar multi-wavelength behaviour

Author

Raiteri, C. M., Villata, M., Carnerero, M. I., Kurtanidze, S. O., Mirzaqulov, D. O., Benítez, E., Bonnoli, G., Carosati, D., Acosta-Pulido, J. A., Agudo, I., Andreeva, T. S., Apolonio, G., Bachev, R., Borman, G. A., Bozhilov, V., Brown, L. F., Carbonell, W., Casadio, C., Chen, W. P., Damljanovic, G., Ehgamberdiev, S. A., Elsaesser, D., Escudero, J., Feige, M., Fuentes, A., Gabellini, D., Gazeas, K., Giroletti, M., Grishina, T. S., Gupta, A. C., Gurwell, M. A., Hagen-Thorn, V. A., Hamed, G. M., Hiriart, D., Hodges, M., ivanidze, R. Z., Ivanov, D. V., Joner, M. D., Jorstad, S. G., Jovanovic, M. D., Kiehlmann, S., Kimeridze, G. N., Kopatskaya, E. N., Kovalev, Yu. A., Kovalev, Y. Y., Kurtanidze, O. M., Kurtenkov, A., Larionova, E. G., Lessing, A., Lin, H. C., López, J. M., Lorey, C., Ludwig, J., Marchili, N., Marchini, A., Marscher, A. P., Matsumoto, K., Max-Moerbeck, W., Mihov, B., Minev, M., Mingaliev, M. G., Modaressi, A., Morozova, D. A., Mortari, F., Mufakharov, T. V., Myserlis, I., Nikolashvili, M. G., Pearson, T. J., Popkov, A. V., Rahimov, I. A., Readhead, A. C. S., Reinhart, D., Reeves, R., Righini, S., Romanov, F. D., Savchenko, S. S., Semkov, E., Shishkina, E. V., Sigua, L. A., Slavcheva-Mihova, L., Sotnikova, Yu. V., Steineke, R., Stojanovic, M., Strigachev, A., Takey, A., Traianou, E., Troitskaya, Yu. V., Troitskiy, I. S., Tsai, A. L., Valcheva, A., Vasilyev, A. A., Verna, G., Vince, O., Vrontaki, K., Weaver, Z. R., Webb, J., Yuldoshev, Q. X., Zaharieva, E., and Zhovtan, A. V.

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

Blazars are beamed active galactic nuclei known for their strong multi-wavelength variability on timescales from years down to minutes. We aim to investigate the suitability of the twisting jet model presented in previous works to explain the multi-wavelength behaviour of BL Lacertae, the prototype of one of the blazar classes. According to this model, the jet is inhomogeneous, curved, and twisting, and the long-term variability is due to changes in the Doppler factor due to variations in the orientation of the jet-emitting regions. We analysed optical data of the source obtained during monitoring campaigns organised by the Whole Earth Blazar Telescope (WEBT) in 2019-2022, together with radio data from the WEBT and other teams, and gamma-ray data from the Fermi satellite. In this period, BL Lacertae underwent an extraordinary activity phase, reaching its historical optical and gamma-ray brightness maxima. The application of the twisting jet model to the source light curves allows us to infer the wiggling motion of the optical, radio, and gamma-ray jet-emitting regions. The optical-radio correlation shows that the changes in the radio viewing angle follow those in the optical viewing angle by about 120 days, and it suggests that the jet is composed of plasma filaments, which is in agreement with some radio high-resolution observations of other sources. The gamma-ray emitting region is found to be co-spatial with the optical one, and the analysis of the gamma-optical correlation is consistent with both the geometric interpretation and a synchrotron self-Compton (SSC) origin of the high-energy photons. We propose a geometric scenario where the jet is made up of a pair of emitting plasma filaments in a sort of double-helix curved rotating structure, whose wiggling motion produces changes in the Doppler beaming and can thus explain the observed multi-wavelength long-term variability., Comment: In press for A&A

Published
2024
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3. Evidence for a toroidal magnetic field in the core of 3C 84

Author

Paraschos, G. F., Debbrecht, L. C., Kramer, J. A., Traianou, E., Liodakis, I., Krichbaum, T. P., Kim, J. -Y., Janssen, M., Nair, D. G., Savolainen, T., Ros, E., Bach, U., Hodgson, J. A., Lisakov, M., MacDonald, N. R., and Zensus, J. A.

Subjects
Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Astrophysics of Galaxies
Abstract

The spatial scales of relativistic radio jets, probed by relativistic magneto-hydrodynamic jet launching simulations (RMHDs) and by most very-long-baseline interferometry (VLBI) observations differ by an order of magnitude. Bridging the gap between these RMHD simulations and VLBI observations requires selecting nearby active galactic nuclei (AGN), the parsec-scale region of which can be resolved. 3C 84 is a nearby bright AGN fulfilling the necessary requirements: it is launching a powerful, relativistic jet powered by a central supermassive black hole, while also being very bright. Using 22 GHz global VLBI measurements of 3C 84 we aim to study its sub-parsec region in both total intensity and linear polarisation, to explore the properties of this jet, with a linear resolution of $\sim0.1$ parsec. We test different simulation setups by altering the bulk Lorentz factor $\Gamma$ of the jet, as well as the magnetic field configuration (toroidal, poloidal, helical). We confirm the persistence of a limb brightened structure, which reaches deep into the sub-parsec region. The corresponding electric vector position angles (EVPAs) follow the bulk jet flow inside but tend to be orthogonal to it near the edges. Our state-of-the-art RMHD simulations show that this geometry is consistent with a spine-sheath model, associated with a mildly relativistic flow and a toroidal magnetic field configuration., Comment: 10 pages, 8 figures, accepted for publication in Astronomy and Astrophysics

Published
2024
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4. Broadband Multi-wavelength Properties of M87 during the 2018 EHT Campaign including a Very High Energy Flaring Episode

Author

Algaba, J. C., Balokovic, M., Chandra, S., Cheong, W. Y., Cui, Y. Z., D'Ammando, F., Falcone, A. D., Ford, N. M., Giroletti, M., Goddi, C., Gurwell, M. A., Hada, K., Haggard, D., Jorstad, S., Kaur, A., Kawashima, T., Kerby, S., Kim, J. Y., Kino, M., Kravchenko, E. V., Lee, S. S., Lu, R. S., Markoff, S., Michail, J., Neilsen, J., Nowak, M. A., Principe, G., Ramakrishnan, V., Ripperda, B., Sasada, M., Savchenko, S. S., Sheridan, C., Akiyama, K., Alberdi, A., Alef, W., Anantua, R., Asada, K., Azulay, R., Bach, U., Baczko, A. -K., Ball, D., Bandyopadhyay, B., Barrett, J., Bauböck, M., Benson, B. A., Bintley, D., Blackburn, L., Blundell, R., Bouman, K. L., Bower, G. C., Boyce, H., Bremer, M., Brissenden, R., Britzen, S., Broderick, A. E., Broguiere, D., Bronzwaer, T., Bustamante, S., Carlstrom, J. E., Chael, A., Chan, C. -K., Chang, D. O., Chatterjee, K., Chatterjee, S., Chen, M. -T., Chen, Y., Cheng, X., Cho, I., Christian, P., Conroy, N. S., Conway, J. E., Crawford, T. M., Crew, G. B., Cruz-Osorio, A., Dahale, R., Davelaar, J., De Laurentis, M., Deane, R., Dempsey, J., Desvignes, G., Dexter, J., Dhruv, V., Dihingia, I. K., Doeleman, S. S., Dzib, S. A., Eatough, R. P., Emami, R., Falcke, H., Farah, J., Fish, V. L., Fomalont, E., Ford, H. A., Foschi, M., Fraga-Encinas, R., Freeman, W. T., Friberg, P., Fromm, C. M., Fuentes, A., Galison, P., Gammie, C. F., García, R., Gentaz, O., Georgiev, B., Gold, R., Gómez-Ruiz, A. I., Gómez, J. L., Gu, M., Hesper, R., Heumann, D., Ho, L. C., Ho, P., Honma, M., Huang, C. -W. L., Huang, L., Hughes, D. H., Ikeda, S., Impellizzeri, C. M. V., Inoue, M., Issaoun, S., James, D. J., Jannuzi, B. T., Janssen, M., Jeter, B., Jiang, W., Jiménez-Rosales, A., Johnson, M. D., Jones, A. C., Joshi, A. V., Jung, T., Karuppusamy, R., Keating, G. K., Kettenis, M., Kim, D. -J., Kim, J., Koay, J. Y., Kocherlakota, P., Kofuji, Y., Koch, P. M., Koyama, S., Kramer, C., Kramer, J. A., Kramer, M., Krichbaum, T. P., Kuo, C. -Y., La Bella, N., Levis, A., Li, Z., Lico, R., Lindahl, G., Lindqvist, M., Lisakov, M., Liu, J., Liu, K., Liuzzo, E., Lo, W. -P., Lobanov, A. P., Loinard, L., Lonsdale, C. J., Lowitz, A. E., MacDonald, N. R., Mao, J., Marchili, N., Marrone, D. P., Marscher, A. P., Martí-Vidal, I., Matsushita, S., Matthews, L. D., Medeiros, L., Menten, K. M., Mizuno, I., Mizuno, Y., Montgomery, J., Moran, J. M., Moriyama, K., Moscibrodzka, M., Mulaudzi, W., Müller, C., Müller, H., Mus, A., Musoke, G., Myserlis, I., Nagai, H., Nagar, N. M., Nair, D. G., Nakamura, M., Narayanan, G., Natarajan, I., Nathanail, A., Fuentes, S. Navarro, Ni, C., Oh, J., Okino, H., Olivares, H., Oyama, T., Özel, F., Palumbo, D. C. M., Paraschos, G. Filippos, Park, J., Parsons, H., Patel, N., Pen, U. -L., Pesce, D. W., Piétu, V., PopStefanija, A., Porth, O., Prather, B., Psaltis, D., Pu, H. -Y., Rao, R., Rawlings, M. G., Raymond, A. W., Rezzolla, L., Ricarte, A., Roelofs, F., Romero-Cañizales, C., Ros, E., Roshanineshat, A., Rottmann, H., Roy, A. L., Ruiz, I., Ruszczyk, C., Rygl, K. L. J., Sánchez, S., Sánchez-Argüelles, D., Sánchez-Portal, M., Satapathy, K., Savolainen, T., Schloerb, F. P., Schonfeld, J., Schuster, K. -F., Shao, L., Shen, Z., Small, D., Sohn, B. W., SooHoo, J., Salas, L. D. Sosapanta, Souccar, K., Stanway, J. S., Sun, H., Tazaki, F., Tetarenko, A. J., Tiede, P., Tilanus, R. P. J., Titus, M., Toma, K., Torne, P., Toscano, T., Traianou, E., Trent, T., Trippe, S., Turk, M., van Bemmel, I., van Langevelde, H. J., van Rossum, D. R., Vos, J., Wagner, J., Ward-Thompson, D., Wardle, J., Washington, J. E., Weintroub, J., Wharton, R., Wielgus, M., Wiik, K., Witzel, G., Wondrak, M. F., Wong, G. N., Wu, Q., Yadlapalli, N., Yamaguchi, P., Yfantis, A., Yoon, D., Young, A., Younsi, Z., Yu, W., Yuan, F., Yuan, Y. -F., Zensus, J. A., Zhang, S., Zhao, G. -Y., Zhao, S. -S., Bellazzini, R., Berenji, B., Bissaldi, E., Blandford, R. D., Bonino, R., Bruel, P., Cameron, R. A., Caraveo, P. A., Cavazzuti, E., Cheung, C. C., Ciprini, S., Orestano, P. Cristarella, Cutini, S., Di Lalla, N., Dinesh, A., Di Venere, L., Domínguez, A., Fegan, S. J., Franckowiak, A., Fukazawa, Y., Fusco, P., Gargano, F., Gasbarra, C., Germani, S., Giliberti, M., Grenier, I. A., Hays, E., Horan, D., Kuss, M., Larsson, S., Liodakis, I., Longo, F., Loparco, F., Lovellette, M. N., Maldera, S., Mazziotta, M. N., Mereu, I., Michelson, P. F., Mirabal, N., Mizuno, T., Monzani, M. E., Morselli, A., Negro, M., Omodei, N., Orlando, E., Persic, M., Rainò, S., Rani, B., Reimer, A., Reimer, O., Sánchez-Conde, M., Parkinson, P. M. Saz, Sgrò, C., Siskind, E. J., Spinelli, P., Suson, D. J., Tajima, H., Torres, D. F., Zaharijas, G., Aharonian, F., Benkhali, F. Ait, Aschersleben, J., Ashkar, H., Backes, M., Martins, V. Barbosa, Batzofin, R., Becherini, Y., Berge, D., Böttcher, M., Boisson, C., Bolmont, J., de Lavergne, M. de Bony, Borowska, J., Bouyahiaoui, M., Bradascio, F., Brose, R., Brown, A., Bruno, B., Bulik, T., Burger-Scheidlin, C., Casanova, S., Cecil, R., Celic, J., Cerruti, M., Chand, T., Chen, A., Chibueze, J., Chibueze, O., Czerny, T., Dainotti, M., Dubus, F., Dumm, J., D'Urso, G., Drouhin, A., Durouchoux, P., Fabbian, D., Franczak, D., Funk, M., Gabanyi, J., Gaggero, G., Garcia, N., Geiger, A., Giorgi, M. G., Gleeson, S., Gonzalez, S., Gauthier, G. T., Grasso, P., Hovatta, T., Hyman, J., Kaaret, C., Kirk, D., Lal, S., Lesch, T. M., Lohmann, K., Massaro, C., Mayer, M., Meintjes, P. J., Miral, E., Mirra, A., Neronov, J., Padovani, E., Paccagnella, F., Parisi, E., Piotrowska, A., Pohl, S., Puga, G., Ramirez, L. R., Reville, S., Rowell, D. S., Rudge, M., Rybka, G., Schlenstedt, M. S., Seo, E. S., Svirski, J., Taylor, J. R., Torres, F., Tsujimoto, K., Tosti, F., Volpi, S., Walraven, N. A., Welker, L., Zietkiewicz, M., Abdalla, G., Aleva, C., Benkhali, H. A. Ait, Aldous, M., Amin, M., Aschieri, M. A., de Deus, E., Santos, J. de Los, Fontanot, D., Jorfi, S., Levens, P., Zwart, A. E. E., Oliviero, S., Puglisi, D., Thiel, M., Zaharijas, C., Amaral, F., Boella, L., Holincheck, L., Queiroz, R., Sofue, H., Tellis, G., Wagner, G., Wierzcholska, A., Zacharias, M., Zdziarski, A. A., Zech, A., Zywucka, N., Abe, S., Abhir, J., Abhishek, A., Acciari, V. A., Aguasca-Cabot, A., Agudo, I., Aniello, T., Ansoldi, S., Antonelli, L. A., Engels, A. Arbet, Arcaro, C., Artero, M., Asano, K., Babic, A., de Almeida, U. Barres, Barrio, J. A., Batkovic, I., Bautista, A., Baxter, J., González, J. Becerra, Bednarek, W., Bernardini, E., Bernete, J., Berti, A., Besenrieder, J., Bigongiari, C., Biland, A., Blanch, O., Bonnoli, G., Bosnjak, Z., Bronzini, E., Burelli, I., Busetto, G., Campoy-Ordaz, A., Carosi, A., Carosi, R., Carretero-Castrillo, M., Castro-Tirado, A. J., Cerasole, D., Ceribella, G., Chai, Y., Cifuentes, A., Colombo, E., Contreras, J. L., Cortina, J., Covino, S., D'Amico, G., D'Elia, V., Da Vela, P., Dazzi, F., De Angelis, A., De Lotto, B., de Menezes, R., Delfino, M., Delgado, J., Mendez, C. Delgado, Di Pierro, F., Di Tria, R., Prester, D. Dominis, Donini, A., Dorner, D., Doro, M., Elsaesser, D., Escudero, J., Fariña, L., Fattorini, A., Foffano, L., Font, L., Fröse, S., Fukami, S., López, R. J. García, Garczarczyk, M., Gasparyan, S., Gaug, M., Paiva, J. G. Giesbrecht, Giglietto, N., Giordano, F., Gliwny, P., Godinovic, N., Gradetzke, T., Grau, R., Green, D., Green, J. G., Günther, P., Hadasch, D., Hahn, A., Hassan, T., Heckmann, L., Llorente, J. Herrera, Hrupec, D., Imazawa, R., Ishio, K., Martínez, I. Jiménez, Jormanainen, J., Kayanoki, T., Kerszberg, D., Kluge, G. W., Kobayashi, Y., Kouch, P. M., Kubo, H., Kushida, J., Laínez, M., Lamastra, A., Leone, F., Lindfors, E., Lombardi, S., López-Coto, R., López-Moya, M., López-Oramas, A., Loporchio, S., Lorini, A., Lyard, E., Fraga, B. Machado de Oliveira, Majumdar, P., Makariev, M., Maneva, G., Manganaro, M., Mangano, S., Mannheim, K., Mariotti, M., Martínez, M., Martínez-Chicharro, M., Mas-Aguilar, A., Mazin, D., Menchiari, S., Mender, S., Miceli, D., Miener, T., Miranda, J. M., Mirzoyan, R., González, M. Molero, Molina, E., Mondal, H. A., Moralejo, A., Morcuende, D., Nakamori, T., Nanci, C., Neustroev, V., Nickel, L., Rosillo, M. Nievas, Nigro, C., Nikolic, L., Nilsson, K., Nishijima, K., Ekoume, T. Njoh, Noda, K., Nozaki, S., Ohtani, Y., Okumura, A., Otero-Santos, J., Paiano, S., Paneque, D., Paoletti, R., Paredes, J. M., Peresano, M., Pihet, M., Pirola, G., Podobnik, F., Moroni, P. G. Prada, Prandini, E., Priyadarshi, C., Ribó, M., Rico, J., Righi, C., Sahakyan, N., Saito, T., Saturni, F. G., Schmidt, K., Schmuckermaier, F., Schubert, J. L., Schweizer, T., Sciaccaluga, A., Silvestri, G., Sitarek, J., Sliusar, V., Sobczynska, D., Spolon, A., Stamerra, A., Strišković, J., Strom, D., Strzys, M., Suda, Y., Suutarinen, S., Takahashi, M., Takeishi, R., Tavecchio, F., Temnikov, P., Terauchi, K., Terzic, T., Teshima, M., Truzzi, S., Tutone, A., Ubach, S., van Scherpenberg, J., Acosta, M. Vazquez, Ventura, S., Verna, G., Viale, I., Vigorito, C. F., Vitale, V., Vovk, I., Walter, R., Will, M., Wunderlich, C., Yamamoto, T., Acharyya, A., Adams, C. B., Bangale, P., Bartkoske, J. T., Benbow, W., Christiansen, J. L., Duerr, A., Errando, M., Feng, Q., Foote, G. M., Fortson, L., Furniss, A., Hanlon, W., Hervet, O., Hinrichs, C. E., Holder, J., Humensky, T. B., Jin, W., Johnson, M. N., Kaaret, P., Kertzman, M., Kieda, D., Kleiner, T. K., Korzoun, N., Krennrich, F., Kumar, S., Lang, M. J., Lundy, M., Maier, G., McGrath, C. E., Millard, M. J., Mooney, C. L., Moriarty, P., Mukherjee, R., Ning, W., O'Brien, S., Ong, R. A., Pohl, M., Pueschel, E., Quinn, J., Ragan, K., Reynolds, P. T., Ribeiro, D., Roache, E., Ryan, J. L., Sadeh, I., Saha, L., Santander, M., Sembroski, G. H., Shang, R., Splettstoesser, M., Talluri, A. K., Tucci, J. V., Valverde, J., Vassiliev, V. V., Williams, D. A., Wong, S. L., Chen, Z., Cui, L., Hirota, T., Li, B., Li, G., Liu, Q., Liu, X., Liu, Z., Ma, J., Niinuma, K., Ro, H., Sakai, N., Sawada-Satoh, S., Wajima, K., Wang, J., Wang, N., Xia, B., Yan, H., Yonekura, Y., Zhang, H., Zhao, R., Zhong, W., group, The Event Horizon Telescope - Multi-wavelength science working, Collaboration, The Event Horizon Telescope, Collaboration, The Fermi Large Area Telescope, Collaboration, H. E. S. S., Collaboration, MAGIC, Collaboration, VERITAS, and Collaboration, EAVN

Subjects
Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Astrophysics of Galaxies
Abstract

The nearby elliptical galaxy M87 contains one of the only two supermassive black holes whose emission surrounding the event horizon has been imaged by the Event Horizon Telescope (EHT). In 2018, more than two dozen multi-wavelength (MWL) facilities (from radio to gamma-ray energies) took part in the second M87 EHT campaign. The goal of this extensive MWL campaign was to better understand the physics of the accreting black hole M87*, the relationship between the inflow and inner jets, and the high-energy particle acceleration. Understanding the complex astrophysics is also a necessary first step towards performing further tests of general relativity. The MWL campaign took place in April 2018, overlapping with the EHT M87* observations. We present a new, contemporaneous spectral energy distribution (SED) ranging from radio to very high energy (VHE) gamma-rays, as well as details of the individual observations and light curves. We also conduct phenomenological modelling to investigate the basic source properties. We present the first VHE gamma-ray flare from M87 detected since 2010. The flux above 350 GeV has more than doubled within a period of about 36 hours. We find that the X-ray flux is enhanced by about a factor of two compared to 2017, while the radio and millimetre core fluxes are consistent between 2017 and 2018. We detect evidence for a monotonically increasing jet position angle that corresponds to variations in the bright spot of the EHT image. Our results show the value of continued MWL monitoring together with precision imaging for addressing the origins of high-energy particle acceleration. While we cannot currently pinpoint the precise location where such acceleration takes place, the new VHE gamma-ray flare already presents a challenge to simple one-zone leptonic emission model approaches, and emphasises the need for combined image and spectral modelling., Comment: 46 pages, 23 figures, accepted by Astronomy & Astrophysics on August. 29, 2024

Published
2024
Full Text
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5. Ordered magnetic fields around the 3C 84 central black hole

Author

Paraschos, G. F., Kim, J. -Y., Wielgus, M., Röder, J., Krichbaum, T. P., Ros, E., Agudo, I., Myserlis, I., Moscibrodzka, M., Traianou, E., Zensus, J. A., Blackburn, L., Chan, C. -K., Issaoun, S., Janssen, M., Johnson, M. D., Fish, V. L., Akiyama, K., Alberdi, A., Alef, W., Algaba, J. C., Anantua, R., Asada, K., Azulay, R., Bach, U., Baczko, A. -K., Ball, D., Baloković, M., Barrett, J., Bauböck, M., Benson, B. A., Bintley, D., Blundell, R., Bouman, K. L., Bower, G. C., Boyce, H., Bremer, M., Brinkerink, C. D., Brissenden, R., Britzen, S., Broderick, A. E., Broguiere, D., Bronzwaer, T., Bustamante, S., Byun, D. -Y., Carlstrom, J. E., Ceccobello, C., Chael, A., Chang, D. O., Chatterjee, K., Chatterjee, S., Chen, M. T., Chen, Y., Cheng, X., Cho, I., Christian, P., Conroy, N. S., Conway, J. E., Cordes, J. M., Crawford, T. M., Crew, G. B., Cruz-Osorio, A., Cui, Y., Dahale, R., Davelaar, J., De Laurentis, M., Deane, R., Dempsey, J., Desvignes, G., Dexter, J., Dhruv, V., Doeleman, S. S., Dougal, S., Dzib, S. A., Eatough, R. P., Emami, R., Falcke, H., Farah, J., Fomalont, E., Ford, H. A., Foschi, M., Fraga-Encinas, R., Freeman, W. T., Friberg, P., Fromm, C. M., Fuentes, A., Galison, P., Gammie, C. F., García, R., Gentaz, O., Georgiev, B., Goddi, C., Gold, R., Gómez-Ruiz, A. I., Gómez, J. L., Gu, M., Gurwell, M., Hada, K., Haggard, D., Haworth, K., Hecht, M. H., Hesper, R., Heumann, D., Ho, L. C., Ho, P., Honma, M., Huang, C. L., Huang, L., Hughes, D. H., Ikeda, S., Impellizzeri, C. M. V., Inoue, M., James, D. J., Jannuzi, B. T., Jeter, B., Jaing, W., Jiménez-Rosales, A., Jorstad, S., Joshi, A. V., Jung, T., Karami, M., Karuppusamy, R., Kawashima, T., Keating, G. K., Kettenis, M., Kim, D. -J., Kim, J., Kino, M., Koay, J. Y., Kocherlakota, P., Kofuji, Y., Koch, P. M., Koyama, S., Kramer, C., Kramer, J. A., Kramer, M., Kuo, C. -Y., La Bella, N., Lauer, T. R., Lee, D., Lee, S. -S., Leung, P. K., Levis, A., Li, Z., Lico, R., Lindahl, G., Lindqvist, M., Lisakov, M., Liu, J., Liu, K., Liuzzo, E., Lo, W. -P., Lobanov, A. P., Loinard, L., Lonsdale, C. J., Lowitz, A. E., Lu, R. -S., MacDonald, N. R., Mao, J., Marchili, N., Markoff, S., Marrone, D. P., Marscher, A. P., Martí-Vidal, I., Matsushita, S., Matthews, L. D., Medeiros, L., Menten, K. M., Michalik, D., Mizuno, I., Mizuno, Y., Moran, J. M., Moriyama, K., Mulaudzi, W., Müller, C., Müller, H., Mus, A., Musoke, G., Nadolski, A., Nagai, H., Nagar, N. M., Nakamura, M., Narayanan, G., Natarajan, I., Nathanail, A., Fuentes, S. Navarro, Neilsen, J., Neri, R., Ni, C., Noutsos, A., Nowak, M. A., Oh, J., Okino, H., Olivares, H., Ortiz-León, G. N., Oyama, T., Özel, F., Palumbo, D. C. M., Park, J., Parsons, H., Patel, N., Pen, U. -L., Piétu, V., Plambeck, R., PopStefanija, A., Porth, O., Pötzl, F. M., Prather, B., Preciado-López, J. A., Psaltis, D., Pu, H. -Y., Ramakrishnan, V., Rao, R., Rawlings, M. G., Raymond, A. W., Rezzolla, L., Ricarte, A., Ripperda, B., Roelofs, F., Rogers, A., Romero-Cañizales, C., Roshanineshat, A., Rottmann, H., Roy, A. L., Ruiz, I., Ruszczyk, C., Rygl, K. L. J., Sánchez, S., Sánchez-Argüelles, D., Sánchez-Portal, M., Sasada, M., Satapathy, K., Savolainen, T., Schloerb, F. P., Schonfeld, J., Schuster, K., Shao, L., Shen, Z., Small, D., Sohn, B. W., SooHoo, J., Salas, L. D. Sosapanta, Souccar, K., Sun, H., Tazaki, F., Tetarenko, A. J., Tiede, P., Tilanus, R. P. J., Titus, M., Torne, P., Toscano, T., Trent, T., Trippe, S., Turk, M., van Bemmel, I., van Langevelde, H. J., van Rossum, D. R., Vos, J., Wagner, J., Ward-Thompson, D., Wardle, J., Washington, J. E., Weintroub, J., Wharton, R., Wiik, K., Witzel, G., Wondrak, M. F., Wong, G. N., Wu, Q., Yadlapalli, N., Yamaguchi, P., Yfantis, A., Yoon, D., Young, A., Young, K., Younsi, Z., Yu, W., Yuan, F., Yuan, Y. -F., Zhang, S., Zhao, G. Y., and Zhao, S. -S.

Subjects
Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Astrophysics of Galaxies
Abstract

3C84 is a nearby radio source with a complex total intensity structure, showing linear polarisation and spectral patterns. A detailed investigation of the central engine region necessitates the use of VLBI above the hitherto available maximum frequency of 86GHz. Using ultrahigh resolution VLBI observations at the highest available frequency of 228GHz, we aim to directly detect compact structures and understand the physical conditions in the compact region of 3C84. We used EHT 228GHz observations and, given the limited (u,v)-coverage, applied geometric model fitting to the data. We also employed quasi-simultaneously observed, multi-frequency VLBI data for the source in order to carry out a comprehensive analysis of the core structure. We report the detection of a highly ordered, strong magnetic field around the central, SMBH of 3C84. The brightness temperature analysis suggests that the system is in equipartition. We determined a turnover frequency of $\nu_m=(113\pm4)$GHz, a corresponding synchrotron self-absorbed magnetic field of $B_{SSA}=(2.9\pm1.6)$G, and an equipartition magnetic field of $B_{eq}=(5.2\pm0.6)$G. Three components are resolved with the highest fractional polarisation detected for this object ($m_\textrm{net}=(17.0\pm3.9)$%). The positions of the components are compatible with those seen in low-frequency VLBI observations since 2017-2018. We report a steeply negative slope of the spectrum at 228GHz. We used these findings to test models of jet formation, propagation, and Faraday rotation in 3C84. The findings of our investigation into different flow geometries and black hole spins support an advection-dominated accretion flow in a magnetically arrested state around a rapidly rotating supermassive black hole as a model of the jet-launching system in the core of 3C84. However, systematic uncertainties due to the limited (u,v)-coverage, however, cannot be ignored., Comment: 15 pages, 6 figures, published in A&A

Published
2024
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6. Multi-messenger characterization of Mrk 501 during historically low X-ray and $\gamma$-ray activity

Author

MAGIC collaboration, Abe, H., Abe, S., Acciari, V. A., Agudo, I., Aniello, T., Ansoldi, S., Antonelli, L. A., Engels, A. Arbet, Arcaro, C., Artero, M., Asano, K., Baack, D., Babić, A., Baquero, A., de Almeida, U. Barres, Barrio, J. A., Batković, I., Baxter, J., González, J. Becerra, Bednarek, W., Bernardini, E., Bernardos, M., Berti, A., Besenrieder, J., Bhattacharyya, W., Bigongiari, C., Biland, A., Blanch, O., Bonnoli, G., Bošnjak, Ž., Burelli, I., Busetto, G., Carosi, R., Carretero-Castrillo, M., Castro-Tirado, A. J., Ceribella, G., Chai, Y., Chilingarian, A., Cikota, S., Colombo, E., Contreras, J. L., Cortina, J., Covino, S., D'Amico, G., D'Elia, V., Da Vela, P., Dazzi, F., De Angelis, A., De Lotto, B., Del Popolo, A., Delfino, M., Delgado, J., Mendez, C. Delgado, Depaoli, D., Di Pierro, F., Di Venere, L., Espiñeira, E. Do Souto, Prester, D. Dominis, Donini, A., Dorner, D., Doro, M., Elsaesser, D., Emery, G., Escudero, J., Ramazani, V. Fallah, Fariña, L., Fattorini, A., Foffano, L., Font, L., Fruck, C., Fukami, S., Fukazawa, Y., López, R. J. García, Garczarczyk, M., Gasparyan, S., Gaug, M., Paiva, J. G. Giesbrecht, Giglietto, N., Giordano, F., Gliwny, P., Godinović, N., Grau, R., Green, D., Green, J. G., Hadasch, D., Hahn, A., Hassan, T., Heckmann, L., Herrera, J., Hrupec, D., Hütten, M., Imazawa, R., Inada, T., Iotov, R., Ishio, K., Martínez, I. Jiménez, Jormanainen, J., Kerszberg, D., Kobayashi, Y., Kubo, H., Kushida, J., Lamastra, A., Lelas, D., Leone, F., Lindfors, E., Linhoff, L., Lombardi, S., Longo, F., López-Coto, R., López-Moya, M., López-Oramas, A., Loporchio, S., Lorini, A., Lyard, E., Fraga, B. Machado de Oliveira, Majumdar, P., Makariev, M., Maneva, G., Mang, N., Manganaro, M., Mangano, S., Mannheim, K., Mariotti, M., Martínez, M., Mas-Aguilar, A., Mazin, D., Menchiari, S., Mender, S., Mićanović, S., Miceli, D., Miener, T., Miranda, J. M., Mirzoyan, R., Molina, E., Mondal, H. A., Moralejo, A., Morcuende, D., Moreno, V., Nakamori, T., Nanci, C., Nava, L., Neustroev, V., Rosillo, M. Nievas, Nigro, C., Nilsson, K., Nishijima, K., Ekoume, T. Njoh, Noda, K., Nozaki, S., Ohtani, Y., Oka, T., Okumura, A., Otero-Santos, J., Paiano, S., Palatiello, M., Paneque, D., Paoletti, R., Paredes, J. M., Pavletić, L., Persic, M., Pihet, M., Pirola, G., Podobnik, F., Moroni, P. G. Prada, Prandini, E., Principe, G., Priyadarshi, C., Rhode, W., Ribó, M., Rico, J., Righi, C., Rugliancich, A., Sahakyan, N., Saito, T., Sakurai, S., Satalecka, K., Saturni, F. G., Schleicher, B., Schmidt, K., Schmuckermaier, F., Schubert, J. L., Schweizer, T., Sitarek, J., Sliusar, V., Sobczynska, D., Spolon, A., Stamerra, A., Strišković, J., Strom, D., Strzys, M., Suda, Y., Surić, T., Tajima, H., Takahashi, M., Takeishi, R., Tavecchio, F., Temnikov, P., Terauchi, K., Terzić, T., Teshima, M., Tosti, L., Truzzi, S., Tutone, A., Ubach, S., van Scherpenberg, J., Acosta, M. Vazquez, Ventura, S., Verguilov, V., Viale, I., Vigorito, C. F., Vitale, V., Vovk, I., Walter, R., Will, M., Wunderlich, C., Yamamoto, T., Zarić, D., groups, Other, collaborations, Cerruti, M., Acosta-Pulido, J. A., Apolonio, G., Bachev, R., Baloković, M., Benítez, E., Björklund, I., Bozhilov, V., Brown, L. F., Bugg, A., Carbonell, W., Carnerero, M. I., Carosati, D., Casadio, C., Chamani, W., Chen, W. P., Chigladze, R. A., Damljanovic, G., Epps, K., Erkenov, A., Feige, M., Finke, J., Fuentes, A., Gazeas, K., Giroletti, M., Grishina, T. S., Gupta, A. C., Gurwell, M. A., Heidemann, E., Hiriart, D., Hou, W. J., Hovatta, T., Ibryamov, S., Joner, M. D., Jorstad, S. G., Kania, J., Kiehlmann, S., Kimeridze, G. N., Kopatskaya, E. N., Kopp, M., Korte, M., Kotas, B., Koyama, S., Kramer, J. A., Kunkel, L., Kurtanidze, S. O., Kurtanidze, O. M., Lähteenmäki, A., López, J. M., Larionov, V. M., Larionova, E. G., Larionova, L. V., Leto, C., Lorey, C., Mújica, R., Madejski, G. M., Marchili, N., Marscher, A. P., Minev, M., Modaressi, A., Morozova, D. A., Mufakharov, T., Myserlis, I., Nikiforova, A. A., Nikolashvili, M. G., Ovcharov, E., Perri, M., Raiteri, C. M., Readhead, A. C. S., Reimer, A., Reinhart, D., Righini, S., Rosenlehner, K., Sadun, A. C., Savchenko, S. S., Scherbantin, A., Schneider, L., Schoch, K., Seifert, D., Semkov, E., Sigua, L. A., Singh, C., Sola, P., Sotnikova, Y., Spencer, M., Steineke, R., Stojanovic, M., Strigachev, A., Tornikoski, M., Traianou, E., Tramacere, A., Troitskaya, Yu. V., Troitskiy, I. S., Trump, J. B., Tsai, A., Valcheva, A., Vasilyev, A. A., Verrecchia, F., Villata, M., Vince, O., Vrontaki, K., Weaver, Z. R., Zaharieva, E., and Zottmann, N.

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

We study the broadband emission of Mrk 501 using multi-wavelength observations from 2017 to 2020 performed with a multitude of instruments, involving, among others, MAGIC, Fermi-LAT, NuSTAR, Swift, GASP-WEBT, and OVRO. Mrk 501 showed an extremely low broadband activity, which may help to unravel its baseline emission. Nonetheless, significant flux variations are detected at all wavebands, with the highest occurring at X-rays and very-high-energy (VHE) $\gamma$-rays. A significant correlation ($>$3$\sigma$) between X-rays and VHE $\gamma$-rays is measured, supporting leptonic scenarios to explain the variable parts of the emission, also during low activity. This is further supported when we extend our data from 2008 to 2020, and identify, for the first time, significant correlations between Swift-XRT and Fermi-LAT. We additionally find correlations between high-energy $\gamma$-rays and radio, with the radio lagging by more than 100 days, placing the $\gamma$-ray emission zone upstream of the radio-bright regions in the jet. Furthermore, Mrk 501 showed a historically low activity in X-rays and VHE $\gamma$-rays from mid-2017 to mid-2019 with a stable VHE flux ($>$0.2 TeV) of 5% the emission of the Crab Nebula. The broadband spectral energy distribution (SED) of this 2-year-long low-state, the potential baseline emission of Mrk 501, can be characterized with one-zone leptonic models, and with (lepto)-hadronic models fulfilling neutrino flux constraints from IceCube. We explore the time evolution of the SED towards the low-state, revealing that the stable baseline emission may be ascribed to a standing shock, and the variable emission to an additional expanding or traveling shock., Comment: 55 pages, 30 figures, 14 tables, accepted by APJS. Corresponding authors are L. Heckmann, D. Paneque, S. Gasparyan, M. Cerruti, and N. Sahakyan

Published
2022
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7. Unravelling the Innermost Jet Structure of OJ 287 with the First GMVA+ALMA Observations

Author

Zhao, Guang-Yao, Gomez, Jose L., Fuentes, Antonio, Krichbaum, Thomas P., Traianou, E., Lico, Rocco, Cho, Ilje, Ros, Eduardo, Komossa, S., Akiyama, Kazunori, Asada, Keiichi, Blackburn, Lindy, Britzen, Silke, Bruni, Gabriele, Crew, Geoffrey, Dahale, Rohan, Dey, Lankeswar, Gold, Roman, Gopakumar, Achamveedu, Issaoun, Sara, Janssen, Michael, Jorstad, Svetlana G., Kim, Jae-Young, Koay, Jun Yi, Kovalev, Yuri Y., Koyama, Shoko, Lobanov, Andrei, Loinard, Laurent, Lu, Rusen, Markoff, Sera, Marscher, Alan P., Marti-Vidal, Ivan, Mizuno, Yosuke, Park, Jongho, Savolainen, Tuomas, and Toscano, Teresa

Subjects
Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Astrophysics of Galaxies
Abstract

We present the first very-long-baseline interferometric (VLBI) observations of the blazar OJ287 carried out jointly with the Global Millimeter VLBI Array (GMVA) and the phased Atacama Large Millimeter/submillimeter Array (ALMA) at 3.5 mm on April 2, 2017. Participation of phased-ALMA not only has improved the GMVA north-south resolution by a factor of ~3, but also has enabled fringe detection with signal-to-noise ratios up to 300 at baselines longer than 2 G{\lambda}. The high sensitivity has motivated us to image the data with the newly developed regularized maximum likelihood imaging methods, revealing the innermost jet structure with unprecedentedly high angular resolution. Our images reveal a compact and twisted jet extending along the northwest direction with two bends within the inner 200 {\mu}as that resembles a precessing jet in projection. The component at the southeastern end shows a compact morphology and high brightness temperature, and is identified as the VLBI core. An extended jet feature that lies at ~200 {\mu}as northwest of the core shows a conical shape in both total and linearly polarized intensity, and a bimodal distribution of the linear polarization electric vector position angle. We discuss the nature of this feature by comparing our observations with models and simulations of oblique and recollimation shocks with various magnetic field configurations. Our high-fidelity images also enabled us to search for possible jet features from the secondary supermassive black hole (SMBH) and test the SMBH binary hypothesis proposed for this source., Comment: 15 pages, 7 figures, accepted for publication in ApJ

Published
2022
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8. New jet feature in the parsec-scale jet of the blazar OJ287 connected to the 2017 teraelectronvolt flaring activity

Author

Lico, R., Casadio, C., Jorstad, S. G., Gomez, J. L., Marscher, A. P., Traianou, E., Kim, J. Y., Zhao, G. Y., Fuentes, A., Cho, I., Krichbaum, T. P., Hervet, O., O'Brien, S., Boccardi, B., Myserlis, I., Agudo, I., Alberdi, A., Weaver, Z. R., and Zensus, J. A.

Subjects
Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Astrophysics of Galaxies
Abstract

In February 2017 the blazar OJ287, one of the best super-massive binary-black-hole-system candidates, was detected for the first time at very high energies (VHEs; E>100GeV) with the ground-based gamma-ray observatory VERITAS. Very high energy gamma rays are thought to be produced in the near vicinity of the central engine in active galactic nuclei. For this reason, and with the main goal of providing useful information for the characterization of the physical mechanisms connected with the observed teraelectronvolt flaring event, we investigate the parsec-scale source properties by means of high-resolution very long baseline interferometry observations. We use 86 GHz Global Millimeter-VLBI Array (GMVA) observations from 2015 to 2017 and combine them with additional multiwavelength radio observations at different frequencies from other monitoring programs. We investigate the source structure by modeling the brightness distribution with two-dimensional Gaussian components in the visibility plane. In the GMVA epoch following the source VHE activity, we find a new jet feature (labeled K) at about 0.2 mas from the core region and located in between two quasi-stationary components (labeled S1 and S2). Multiple periods of enhanced activity are detected at different radio frequencies before and during the VHE flaring state. Based on the findings of this work, we identify as a possible trigger for the VHE flaring emission during the early months of 2017 the passage of a new jet feature through a recollimation shock (represented by the model-fit component S1) in a region of the jet located at a de-projected distance of about 10 pc from the radio core., Comment: 5 pages, 3 figure, 1 table

Published
2022
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9. The Variability of the Black-Hole Image in M87 at the Dynamical Time Scale

Author

Satapathy, Kaushik, Psaltis, Dimitrios, Ozel, Feryal, Medeiros, Lia, Dougall, Sean T., Chan, Chi-kwan, Wielgus, Maciek, Prather, Ben S., Wong, George N., Gammie, Charles F., Akiyama, Kazunori, Alberdi, Antxon, Alef, Walter, Algaba, Juan Carlos, Anantua, Richard, Asada, Keiichi, Azulay, Rebecca, Baczko, Anne-Kathrin, Ball, David R., Baloković, Mislav, Barrett, John, Benson, Bradford A., Bintley, Dan, Blackburn, Lindy, Blundell, Raymond, Boland, Wilfred, Bouman, Katherine L., Bower, Geoffrey C., Boyce, Hope A., Bremer, Michael, Brinkerink, Christiaan D., Brissenden, Roger, Britzen, Silke, Broderick, Avery E., Broguiere, Dominique, Bronzwaer, Thomas, Bustamente, Sandra, Byun, Do-Young, Carlstrom, John E., Chael, Andrew, Chatterjee, Koushik, Chatterjee, Shami, Chen, Ming-Tang, Chen, Yongjun, Cho, Ilje, Christian, Pierre, Conway, John E., Cordes, James M., Crawford, Thomas, Crew, Geoffrey B., Osorio, Alejandro Cruz, Cui, Yuzhu, Davelaar, Jordy, De Laurentis, Mariafelicia, Deane, Roger, Dempsey, Jessica T., Desvignes, Gregory, Dexter, Jason, Doeleman, Sheperd S., Eatough, Ralph, Falcke, Heino, Farah, Joseph R., Fish, Vincent, Fomalont, Edward B., Ford, H. Alyson, Fraga-Encinas, Raquel, Friberg, Per, Fromm, Christian M., Fuentes, Antonio, Galison, Peter, García, Roberto, Gentaz, Olivier, Georgiev, Boris, Goddi, Ciriaco, Gold, Roman, Gomez-Ruiz, Arturo I., Gómez, Jose L., Gu, Minfeng, Gurwell, Mark A., Hada, Kazuhiro, Haggard, Daryl, Hecht, Michael, Hesper, Ronald, Ho, Luis C., Ho, Paul T., Honma, Mareki, Huang, Chih-Wei L., Huang, Lei, Hughes, David H., Ikeda, Shiro, Inoue, Makoto, Issaoun, Sara, James, David J., Jannuzi, Buell T., Janssen, Michael, Jeter, Britton, Jiang, Wu, Rosales, Alejandra Jimenez, Johnson, Michael D., Jorstad, Svetlana G., Jung, Taehyun, Karami, Mansour, Karuppusamy, Ramesh, Kawashima, Tomohisa, Keating, Garrett K., Kettenis, Mark, Kim, Dong-Jin, Kim, Jae-Young, Kim, Jongsoo, Kim, Junhan, Kino, Motoki, Koay, Jun Yi, Kofuji, Yutaro, Koch, Patrick M., Koyama, Shoko, Kramer, Carsten, Kramer, Michael, Krichbaum, Thomas P., Kuo, Cheng-Yu, Lauer, Tod R., Lee, Sang-Sung, Levis, Aviad, Li, Yan-Rong, Li, Zhiyuan, Lindqvist, Michael, Lico, Rocco, Lindahl, Greg, Liu, Jun, Liu, Kuo, Liuzzo, Miss Elisabetta, Lo, Wen-Ping, Lobanov, Andrei, Loinard, Laurent, Lonsdale, Colin J., Lu, Rusen, MacDonald, Nicholas R., Mao, Jirong, Marchili, Nicola, Markoff, Sera, Marrone, Daniel, Marscher, Alan P., Marti-Vidal, Ivan, Matsushita, Satoki, Matthews, Lynn, Menten, Karl M., Mizuno, Izumi, Mizuno, Yosuke, Moran, James, Moriyama, Kotaro, Moscibrodzka, Monika, Muller, Cornelia, Mejias, Alejandro M., Musoke, Gibwa, Nagai, Hiroshi, Nagar, Neil M., Nakamura, Masanori, Narayan, Ramesh, Narayanan, Gopal, Natarajan, Iniyan, Nathanail, Antonios, Neilsen, Joey, Neri, Roberto, Ni, Chunchong, Noutsos, Aristeidis, Nowak, Michael A., Okino, Hiroki, Olivares, Hector, Ortiz-Leon, Gisela N., Oyama, Tomoaki, Palumbo, Daniel C., Park, Jongho, Patel, Nimesh A., Pen, Ue-Li, Pesce, Dominic W., Pietu, Vincent, Plambeck, Richard L., PopStefanija, Aleksandar, Porth, Oliver, Potzl, Felix, Preciado-López, Jorge A., Pu, Hung-Yi, Ramakrishnan, Venkatessh, Rao, Ramprasad, Rawlings, Mark, Raymond, Alexander W., Rezzolla, Luciano, Ripperda, Bart, Roelofs, Freek, Rogers, Alan E. E., Ros, Eduardo, Rose, Mel, Roshanineshat, Arash, Rottmann, Helge, Roy, Alan L., Ruszczyk, Chet, Rygl, Kazi, Sanchez, Salvador, Sanchez-Arguelles, David, Sasada, Mahito, Savolainen, Tuomas, Schloerb, F Peter, Schuster, Karl-Friedrich, Shao, Lijing, Shen, Zhi-Qiang, Small, Des, Sohn, Bong Won, SooHoo, Jason, Sun, He, Tazaki, Fumie, Tetarenko, Alexandra J., Tiede, Paul, Tilanus, Remo, Titus, Michael, Toma, Kenji, Torne, Pablo, Traianou, E., Trent, Tyler, Trippe, Sascha, van Bemmel, Ilse, van Langevelde, Huib Jan, van Rossum, Daniel R., Wagner, Jan, Ward-Thompson, Derek, Wardle, John F., Weintroub, Jonathan, Wex, Norbert, Wharton, Robert, Wiik, Kaj, Wu, Qingwen, Yoon, DooSoo, Young, Andre, Young, Ken H., Younsi, Ziri, Yuan, Feng, Yuan, Ye-Fei, Zensus, J. Anton, Zhao, Guang-Yao, and Zhao, Shan-Shan

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

The black-hole images obtained with the Event Horizon Telescope (EHT) are expected to be variable at the dynamical timescale near their horizons. For the black hole at the center of the M87 galaxy, this timescale (5-61 days) is comparable to the 6-day extent of the 2017 EHT observations. Closure phases along baseline triangles are robust interferometric observables that are sensitive to the expected structural changes of the images but are free of station-based atmospheric and instrumental errors. We explored the day-to-day variability in closure phase measurements on all six linearly independent non-trivial baseline triangles that can be formed from the 2017 observations. We showed that three triangles exhibit very low day-to-day variability, with a dispersion of $\sim3-5^\circ$. The only triangles that exhibit substantially higher variability ($\sim90-180^\circ$) are the ones with baselines that cross visibility amplitude minima on the $u-v$ plane, as expected from theoretical modeling. We used two sets of General Relativistic magnetohydrodynamic simulations to explore the dependence of the predicted variability on various black-hole and accretion-flow parameters. We found that changing the magnetic field configuration, electron temperature model, or black-hole spin has a marginal effect on the model consistency with the observed level of variability. On the other hand, the most discriminating image characteristic of models is the fractional width of the bright ring of emission. Models that best reproduce the observed small level of variability are characterized by thin ring-like images with structures dominated by gravitational lensing effects and thus least affected by turbulence in the accreting plasmas., Comment: Accepted for Publication in ApJ

Published
2021
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10. The jet collimation profile at high resolution in BL Lacertae

Author

Casadio, C., MacDonald, N. R., Boccardi, B., Jorstad, S. G., Marscher, A. P., Krichbaum, T. P., Hodgson, J. A., Kim, J-Y., Traianou, E., Weaver, Z. R., Garrido, M. Gómez, García, J. González, Kallunki, J., Lindqvist, M., Sánchez, S., Yang, J., and Zensus, J. A.

Subjects
Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

Controversial studies on the jet collimation profile of BL Lacertae (BL Lac), the eponymous blazar of BL Lac objects class, complicate the scenario in this already puzzling class of objects. Understanding the jet geometry, in connection with the jet kinematics and the physical conditions in the surrounding medium, is fundamental to better constrain the formation, acceleration and collimation mechanisms in extragalactic jets. With the aim of investigating the jet geometry in the innermost regions of the jet of BL Lac, and solving the controversy, we explore the radio jet in this source, using high resolution millimeter-wave VLBI data. We collect 86GHz GMVA and 43GHz VLBA data to obtain stacked images that we use to infer the jet collimation profile by means of two comparable methods. We analyze the kinematics at 86GHz, and we discuss it in the context of the jet expansion. Finally we consider a possible implication of the Bondi sphere in shaping the different expanding region observed along the jet. We found that the jet in BL Lac expands with an overall conical geometry. A higher expanding rate region is observed between ~5 and 10 pc (de-projected) from the black hole. Such a region is associated with the decrease in brightness usually observed in high-frequency VLBI images of BL Lac. The jet retrieves the original jet expansion around 17 pc, where the presence of a recollimation shock is supported by both the jet profile and the 15GHz kinematics (MOJAVE survey). The change in the jet expansion profile occurring at ~5 pc could be associated with a change in the external pressure profile in correspondence of the Bondi radius (~3.3X10$^5$$R_s$)., Comment: 10 pages, 12 figures. Accepted for publication in Astronomy & Astrophysics

Published
2021
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11. Observation of a sudden cessation of a very-high-energy gamma-ray flare in PKS 1510-089 with H.E.S.S. and MAGIC in May 2016

Author

Collaboration, H. E. S. S., Abdalla, H., Adam, R., Aharonian, F., Benkhali, F. Ait, Angüner, E. O., Arcaro, C., Arm, C., Armstrong, T., Ashkar, H., Backes, M., Baghmanyan, V., Martins, V. Barbosa, Barnacka, A., Barnard, M., Becherini, Y., Berge, D., Bernlöhr, K., Bi, B., Böttcher, M., Boisson, C., Bolmont, J., Bonnefoy, S., de Lavergne, M. de Bony, Bregeon, J., Breuhaus, M., Brun, F., Brun, P., Bryan, M., Büchele, M., Bulik, T., Bylund, T., Caroff, S., Carosi, A., Casanova, S., Ch, T., Ch, S., Chen, A., Cotter, G., Curyło, M., Mbarubucyeye, J. Damascene, Davids, I. D., Davies, J., Deil, C., Devin, J., deWilt, P., Dirson, L., Djannati-Ataï, A., Dmytriiev, A., Donath, A., Doroshenko, V., Dyks, J., Egberts, K., Eichhorn, F., Einecke, S., Emery, G., Ernenwein, J. -P., Feijen, K., Fegan, S., Fiasson, A., de Clairfontaine, G. Fichet, Filipovic, M., Fontaine, G., Funk, S., Füßling, M., Gabici, S., Gallant, Y. A., Giavitto, G., Giunti, L., Glawion, D., Glicenstein, J. F., Gottschall, D., Grondin, M. -H., Hahn, J., Haupt, M., Hermann, G., Hinton, J. A., Hofmann, W., Hoischen, C., Holch, T. L., Holler, M., Hörbe, M., Horns, D., Huber, D., Jamrozy, M., Jankowsky, D., Jankowsky, F., Jardin-Blicq, A., Joshi, V., Jung-Richardt, I., Kastendieck, M. A., Katarzyński, K., Katz, U., Khangulyan, D., Khélifi, B., Klepser, S., Kluźniak, W., Komin, Nu., Konno, R., Kosack, K., Kostunin, D., Kreter, M., Lamanna, G., Lemière, A., Lemoine-Goumard, M., Lenain, J. -P., Levy, C., Lohse, T., Lypova, I., Mackey, J., Majumdar, J., Malyshev, D., Mar, V., Marchegiani, P., Marcowith, A., Mares, A., Martí-Devesa, G., Marx, R., Maurin, G., Meintjes, P. J., Meyer, M., Mitchell, A. M. W., Moderski, R., Mohamed, M., Mohrmann, L., Montanari, A., Moore, C., Morris, P., Moulin, E., Muller, J., Murach, T., Nakashima, K., Nayerhoda, A., de Naurois, M., Ndiyavala, H., Niederwanger, F., Niemiec, J., Oakes, L., O'Brien, P., Odaka, H., Ohm, S., Olivera-Nieto, L., Wilhelmi, E. de Ona, Ostrowski, M., Panter, M., Panny, S., Parsons, R. D., Peron, G., Peyaud, B., Piel, Q., Pita, S., Poireau, V., Noel, A. Priyana, Prokhorov, D. A., Prokoph, H., Pühlhofer, G., Punch, M., Quirrenbach, A., Raab, S., Rauth, R., Reichherzer, P., Reimer, A., Reimer, O., Remy, Q., Renaud, M., Rieger, F., Rinchiuso, L., Romoli, C., Rowell, G., Rudak, B., Ruiz-Velasco, E., Sahakian, V., Sailer, S., Sanchez, D. A., Santangelo, A., Sasaki, M., Scalici, M., Schüssler, F., Schutte, H. M., Schwanke, U., Schwemmer, S., Seglar-Arroyo, M., Senniappan, M., Seyffert, A. S., Shafi, N., Shiningayamwe, K., Simoni, R., Sinha, A., Sol, H., Specovius, A., Spencer, S., Spir-Jacob, M., Stawarz, Ł., Sun, L., Steenkamp, R., Stegmann, C., Steinmassl, S., Steppa, C., Takahashi, T., Tavernier, T., Taylor, A. M., Terrier, R., Tiziani, D., Tluczykont, M., Tomankova, L., Trichard, C., Tsirou, M., Tuffs, R., Uchiyama, Y., van der Walt, D. J., van Eldik, C., van Rensburg, C., van Soelen, B., Vasileiadis, G., Veh, J., Venter, C., Vincent, P., Vink, J., Völk, H. J., Vuillaume, T., Wadiasingh, Z., Wagner, S. J., Watson, J., Werner, F., White, R., Wierzcholska, A., Wong, Yu Wun, Yusafzai, A., Zacharias, M., Zanin, R., Zargaryan, D., Zdziarski, A. A., Zech, A., Zhu, S. J., Zorn, J., Zouari, S., Żywucka, N., Collaboration, MAGIC, Acciari, V. A., Ansoldi, S., Antonelli, L. A., Engels, A. Arbet, Asano, K., Baack, D., Babić, A., Baquero, A., de Almeida, U. Barres, Barrio, J. A., González, J. Becerra, Bednarek, W., Bellizzi, L., Bernardini, E., Berti, A., Besenrieder, J., Bhattacharyya, W., Bigongiari, C., Bil, A., Blanch, O., Bonnoli, G., Bošnjak, Ž., Busetto, G., Carosi, R., Ceribella, G., Cerruti, M., Chai, Y., Chilingarian, A., Cikota, S., Colak, S. M., Colin, U., Colombo, E., Contreras, J. L., Cortina, J., Covino, S., D'Amico, G., D'Elia, V., Da Vela, P., Dazzi, F., De Angelis, A., De Lotto, B., Delfino, M., Delgado, J., Depaoli, D., Di Pierro, F., Di Venere, L., neira, E. Do Souto Espi\, Prester, D. Dominis, Donini, A., Dorner, D., Doro, M., Elsaesser, D., Ramazani, V. Fallah, Fattorini, A., Ferrara, G., Foffano, L., Fonseca, M. V., Font, L., Fruck, C., Fukami, S., López, R. J. García, Garczarczyk, M., Gasparyan, S., Gaug, M., Giglietto, N., Giordano, F., Gliwny, P., Godinović, N., Green, D., Hadasch, D., Hahn, A., Heckmann, L., Herrera, J., Hoang, J., Hrupec, D., Hütten, M., Inada, T., Inoue, S., Ishio, K., Iwamura, Y., Jouvin, L., Kajiwara, Y., Karjalainen, M., Kerszberg, D., Kobayashi, Y., Kubo, H., Kushida, J., Lamastra, A., Lelas, D., Leone, F., Lindfors, E., Lombardi, S., Longo, F., López, M., López-Coto, R., López-Oramas, A., Loporchio, S., Fraga, B. Machado de Oliveira, Maggio, C., Majumdar, P., Makariev, M., Mallamaci, M., Maneva, G., Manganaro, M., Mannheim, K., Maraschi, L., Mariotti, M., Martínez, M., Mazin, D., Mender, S., Mićanović, S., Miceli, D., Miener, T., Minev, M., Mir, J. M., Mirzoyan, R., Molina, E., Moralejo, A., Morcuende, D., Moreno, V., Moretti, E., Munar-Adrover, P., Neustroev, V., Nigro, C., Nilsson, K., Ninci, D., Nishijima, K., Noda, K., Nozaki, S., Ohtani, Y., Oka, T., Otero-Santos, J., Palatiello, M., Paneque, D., Paoletti, R., Paredes, J. M., Pavletić, L., nil, P. Pe\, Perennes, C., Persic, M., Moroni, P. G. Prada, Pr, E., Priyadarshi, C., Puljak, I., Rhode, W., Ribó, M., Rico, J., Righi, C., Rugliancich, A., Saha, L., Sahakyan, N., Saito, T., Sakurai, S., Satalecka, K., Schleicher, B., Schmidt, K., Schweizer, T., Sitarek, J., Šnidarić, I., Sobczynska, D., Spolon, A., Stamerra, A., Strom, D., Strzys, M., Suda, Y., Surić, T., Takahashi, M., Tavecchio, F., Temnikov, P., Terzić, T., Teshima, M., Torres-Albà, N., Tosti, L., Truzzi, S., van Scherpenberg, J., Vanzo, G., Acosta, M. Vazquez, Ventura, S., Verguilov, V., Vigorito, C. F., Vitale, V., Vovk, I., Will, M., Zarić, D., Jorstad, S. G., Marscher, A. P., Boccardi, B., Casadio, C., Hodgson, J., Kim, J. -Y., Krichbaum, T. P., Lähteenmäki, A., Tornikoski, M., Traianou, E., and Weaver, Z. R.

Subjects
Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Astrophysics of Galaxies
Abstract

The flat spectrum radio quasar (FSRQ) PKS 1510-089 is known for its complex multiwavelength behavior, and is one of only a few FSRQs detected at very high energy (VHE, $E>100\,$GeV) $\gamma$-rays. VHE $\gamma$-ray observations with H.E.S.S. and MAGIC during late May and early June 2016 resulted in the detection of an unprecedented flare, which reveals for the first time VHE $\gamma$-ray intranight variability in this source. While a common variability timescale of $1.5\,$hr is found, there is a significant deviation near the end of the flare with a timescale of $\sim 20\,$min marking the cessation of the event. The peak flux is nearly two orders of magnitude above the low-level emission. For the first time, curvature is detected in the VHE $\gamma$-ray spectrum of PKS 1510-089, which is fully explained through absorption by the extragalactic background light. Optical R-band observations with ATOM reveal a counterpart of the $\gamma$-ray flare, even though the detailed flux evolution differs from the VHE ightcurve. Interestingly, a steep flux decrease is observed at the same time as the cessation of the VHE flare. In the high energy (HE, $E>100\,$MeV) $\gamma$-ray band only a moderate flux increase is observed with Fermi-LAT, while the HE $\gamma$-ray spectrum significantly hardens up to a photon index of 1.6. A search for broad-line region (BLR) absorption features in the $\gamma$-ray spectrum indicates that the emission region is located outside of the BLR. Radio VLBI observations reveal a fast moving knot interacting with a standing jet feature around the time of the flare. As the standing feature is located $\sim 50\,$pc from the black hole, the emission region of the flare may have been located at a significant distance from the black hole. If this correlation is indeed true, VHE $\gamma$ rays have been produced far down the jet where turbulent plasma crosses a standing shock., Comment: 25 pages, 17 figures. Accepted for publication by Astronomy & Astrophysics. Corresponding authors: M. Zacharias, J. Sitarek, D. Sanchez, T. Terzic

Published
2020
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12. The WISSH QSOs project IX. Cold gas content and environment of luminous QSOs at z~2.4-4.7

Author

Bischetti, M., Feruglio, C., Piconcelli, E., Duras, F., Pèrez-Torres, M., Herrero, R., Venturi, G., Carniani, S., Bruni, G., Gavignaud, I., Testa, V., Bongiorno, A., Brusa, M., Circosta, C., Cresci, G., D'Odorico, V., Maiolino, R., Marconi, A., Mingozzi, M., Pappalardo, C., Perna, M., Traianou, E., Travascio, A., Vietri, G., Zappacosta, L., and Fiore, F.

Subjects
Astrophysics - Astrophysics of Galaxies
Abstract

Sources at the brightest end of QSO luminosity function during the peak epoch of star formation and black hole accretion (z~2-4, i.e. Cosmic noon) are privileged sites to study the feeding & feedback cycle of massive galaxies. We perform the first systematic study of cold gas properties in the most luminous QSOs, by characterising their host-galaxies and environment. We analyse ALMA, NOEMA and JVLA observations of FIR continuum, CO and [CII] emission lines in eight QSOs ($L_{\rm Bol}>3\times10^{47}$ erg/s) from the WISSH sample at z~2.4-4.7. We report a 100% emission line detection rate and a 80% detection rate in continuum emission, and we find CO emission to be consistent with the steepest CO ladders observed so far. Sub-mm data reveal presence of (one or more) bright companion galaxies around 80% of WISSH QSOs, at projected distances of 6-130 kpc. We observe a variety of sizes for the molecular gas reservoirs (1.7-10 kpc), associated with rotating disks with disturbed kinematics. WISSH QSOs typically show lower CO luminosity and higher star formation efficiency than FIR matched, z~0-3 main-sequence galaxies, implying that, given the observed SFR ~170-1100 $M_\odot$/yr, molecular gas is converted into stars on <50 Myr. Most targets show extreme dynamical to black-hole mass ratios $M_{\rm dyn}/M_{\rm BH}\sim3-10$, two orders of magnitude smaller than local relations. The molecular gas fraction in WISSH hosts is lower by a factor of ~10-100 than in star forming galaxies with similar $M_*$. WISSH QSOs undergo an intense growth phase of both the central SMBH and host-galaxy. They pinpoint high-density sites where giant galaxies assemble and mergers play a major role in the build-up of the final host-galaxy mass. The observed low molecular gas fraction and short depletion timescale are likely due to AGN feedback, as traced by fast AGN-driven ionised outflows in all our targets., Comment: Accepted for publication in A&A

Published
2020
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13. Two Flares with One Shock: the Interesting Case of 3C 454.3

Author

Liodakis, I., Blinov, D., Jorstad, S. G., Arkharov, A. A., Di Paola, A., Efimova, N. V., Grishina, T. S., Kiehlmann, S., Kopatskaya, E. N., Larionov, V. M., Larionova, L. V., Larionova, E. G., Marscher, A. P., Morozova, D. A., Nikiforova, A. A., Pavlidou, V., Traianou, E., Troitskaya, Yu. V., Troitsky, I. S., Uemura, M., and Weaver, Z. R.

Subjects
Astrophysics - High Energy Astrophysical Phenomena
Abstract

The quasar 3C 454.3 is a blazar known for its rapid and violent outbursts seen across the electromagnetic spectrum. Using gamma-ray, X-ray, multi-band optical, and very long baseline interferometric data we investigate the nature of two such events that occurred in 2013 and 2014 accompanied by strong variations in optical polarization, including a 230 degree electric vector position angle (EVPA) rotation. Our results suggest that a single disturbance was responsible for both flaring events. We interpret the disturbance as a shock propagating down the jet. Under this interpretation the 2013-flare originated most likely due to changes in the viewing angle caused by perhaps a bent or helical trajectory of the shock upstream of the radio core. The 2014-flare and optical polarization behavior are the result of the shock exiting the 43 GHz radio core, suggesting that shock crossings are one of the possible mechanisms for EVPA rotations., Comment: 14 pages, 10 figures, 2 Tables, accepted for publication in The Astrophysical Journal

Published
2020
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14. Multiwavelength behaviour of the blazar 3C279: decade-long study from $\gamma$-ray to radio

Author

Larionov, V. M., Jorstad, S. G., Marscher, A. P., Villata, M., Raiteri, C. M., Smith, P. S., Agudo, I., Savchenko, S. S., Morozova, D. A., Acosta-Pulido, J. A., Aller, M. F., Aller, H. D., Andreeva, T. S., Arkharov, A. A., Bachev, R., Bonnoli, G., Borman, G. A., Bozhilov, V., Calcidese, P., Carnerero, M. I., Carosati, D., Casadio, C., Chen, W. -P., Damljanovic, G., Dementyev, A. V., Di Paola, A., Frasca, A., Fuentes, A., Gómez, J. L., Gónzalez-Morales, P., Giunta, A., Grishina, T. S., Gurwell, M. A., Hagen-Thorn, V. A., Hovatta, T., Ibryamov, S., Joshi, M., Kiehlmann, S., Kim, J. -Y., Kimeridze, G. N., Kopatskaya, E. N., Kovalev, Yu. A., Kovalev, Y. Y., Kurtanidze, O. M., Kurtanidze, S. O., Lähteenmäki, A., Lázaro, C., Larionova, L. V., Larionova, E. G., Leto, G., Marchini, A., Matsumoto, K., Mihov, B., Minev, M., Mingaliev, M. G., Mirzaqulov, D., Dimitrova, R. V. Muñoz, Myserlis, I., Nikiforova, A. A., Nikolashvili, M. G., Nizhelsky, N. A., Ovcharov, E., Pressburger, L. D., Rakhimov, I. A., Righini, S., Rizzi, N., Sadakane, K., Sadun, A. C., Samal, M. R., Sanchez, R. Z., Semkov, E., Sergeev, S. G., Sigua, L. A., Slavcheva-Mihova, L., Sola, P., Sotnikova, Yu. V., Strigachev, A., Thum, C., Traianou, E., Troitskaya, Yu. V., Troitsky, I. S., Tsybulev, P. G., Vasilyev, A. A., Vince, O., Weaver, Z. R., Williamson, K. E., and Zhekanis, G. V.

Subjects
Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Astrophysics of Galaxies
Abstract

We report the results of decade-long (2008-2018) $\gamma$-ray to 1 GHz radio monitoring of the blazar 3C 279, including GASP/WEBT, $\it{Fermi}$ and $\it{Swift}$ data, as well as polarimetric and spectroscopic data. The X-ray and $\gamma$-ray light curves correlate well, with no delay > 3 hours, implying general co-spatiality of the emission regions. The $\gamma$-ray-optical flux-flux relation changes with activity state, ranging from a linear to a more complex dependence. The behaviour of the Stokes parameters at optical and radio wavelengths, including 43 GHz VLBA images, supports either a predominantly helical magnetic field or motion of the radiating plasma along a spiral path. Apparent speeds of emission knots range from 10 to 37c, with the highest values requiring bulk Lorentz factors close to those needed to explain $\gamma$-ray variability on very short time scales. The Mg II emission line flux in the `blue' and `red' wings correlates with the optical synchrotron continuum flux density, possibly providing a variable source of seed photons for inverse Compton scattering. In the radio bands we find progressive delays of the most prominent light curve maxima with decreasing frequency, as expected from the frequency dependence of the $\tau=1$ surface of synchrotron self-absorption. The global maximum in the 86 GHz light curve becomes less prominent at lower frequencies, while a local maximum, appearing in 2014, strengthens toward decreasing frequencies, becoming pronounced at $\sim5$ GHz. These tendencies suggest different Doppler boosting of stratified radio-emitting zones in the jet., Comment: 21 pages, 18 figures, accepted for publication in MNRAS

Published
2020
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15. Localizing the $\gamma$-ray emitting region in the blazar TXS 2013+370

Author

Traianou, E., Krichbaum, T. P., Boccardi, B., Angioni, R., Rani, B., Liu, J., Ros, E., Bach, U., Sokolovsky, K. V., Kiehlmann, S., Gurwell, M., and Zensus, J. A.

Subjects
Astrophysics - Astrophysics of Galaxies, Astrophysics - High Energy Astrophysical Phenomena
Abstract

The $\gamma$-ray production mechanism and its localization in blazars are still a matter of debate. The main goal of this paper is to constrain the location of the high-energy emission in the blazar TXS 2013+370 and to study the physical and geometrical properties of the inner jet region on sub-pc scales. VLBI observations at 86 GHz and space-VLBI at 22 GHz allowed us to image the jet base with an angular resolution of $\sim$0.4 pc. By employing CLEAN imaging and Gaussian model-fitting, we performed a thorough kinematic analysis, which provided estimates of the jet speed, orientation, and component ejection times. Additionally, we studied the jet expansion profile and used the information on the jet geometry to estimate the location of the jet apex. VLBI data were combined with single-dish measurements to search for correlated activity between the radio and $\gamma$-ray emission. The high-resolution VLBI imaging revealed the existence of a spatially bent jet, described by moving and stationary features. New jet features are observed to emerge from the core, accompanied by flaring activity in radio bands and $\gamma$ rays. The analysis of the transverse jet width profile constrains the location of the mm core to lie $\leq$ 2 pc downstream of the jet apex, and also reveals the existence of a transition from parabolic to conical jet expansion at a distance of $\sim$54 pc from the core, corresponding to $\sim$1.5$\times$10$^{\rm 6}$ Schwarzschild radii. The cross-correlation analysis reveals a strong correlation between the radio and $\gamma$-ray data, with the 1 mm emission lagging $\sim$49 days behind the $\gamma$ rays. Based on this, we infer that the high energy emission is produced at a distance of $\sim$1 pc from the VLBI core, suggesting that the seed photon fields for the external Compton mechanism originate either in the dusty torus or in the broad-line region., Comment: 16 pages, 15 figures, accepted in A&A

Published
2019
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16. Detection of persistent VHE gamma-ray emission from PKS 1510-089 by the MAGIC telescopes during low states between 2012 and 2017

Author

MAGIC Collaboration, Acciari, V. A., Ansoldi, S., Antonelli, L. A., Engels, A. Arbet, Arcaro, C., Baack, D., Babić, A., Banerjee, B., Bangale, P., de Almeida, U. Barres, Barrio, J. A., González, J. Becerra, Bednarek, W., Bernardini, E., Berti, A., Besenrieder, J., Bhattacharyya, W., Bigongiari, C., Biland, A., Blanch, O., Bonnoli, G., Carosi, R., Ceribella, G., Chatterjee, A., Colak, S. M., Colin, P., Colombo, E., Contreras, J. L., Cortina, J., Covino, S., Cumani, P., D'Elia, V., Da Vela, P., Dazzi, F., De Angelis, A., De Lotto, B., Delfino, M., Delgado, J., Di Pierro, F., Domínguez, A., Prester, D. Dominis, Dorner, D., Doro, M., Einecke, S., Elsaesser, D., Ramazani, V. Fallah, Fattorini, A., Fernández-Barral, A., Ferrara, G., Fidalgo, D., Foffano, L., Fonseca, M. V., Font, L., Fruck, C., Gallozzi, S., López, R. J. García, Garczarczyk, M., Gaug, M., Giammaria, P., Godinović, N., Guberman, D., Hadasch, D., Hahn, A., Hassan, T., Herrera, J., Hoang, J., Hrupec, D., Inoue, S., Ishio, K., Iwamura, Y., Kubo, H., Kushida, J., Kuveždić, D., Lamastra, A., Lelas, D., Leone, F., Lindfors, E., Lombardi, S., Longo, F., López, M., López-Oramas, A., Maggio, C., Majumdar, P., Makariev, M., Maneva, G., Manganaro, M., Mannheim, K., Maraschi, L., Mariotti, M., Martínez, M., Masuda, S., Mazin, D., Minev, M., Miranda, J. M., Mirzoyan, R., Molina, E., Moralejo, A., Moreno, V., Moretti, E., Neustroev, V., Niedzwiecki, A., Rosillo, M. Nievas, Nigro, C., Nilsson, K., Ninci, D., Nishijima, K., Noda, K., Nogués, L., Paiano, S., Palacio, J., Paneque, D., Paoletti, R., Paredes, J. M., Pedaletti, G., Peñil, P., Peresano, M., Persic, M., Moroni, P. G. Prada, Prandini, E., Puljak, I., Garcia, J. R., Rhode, W., Ribó, M., Rico, J., Righi, C., Rugliancich, A., Saha, L., Saito, T., Satalecka, K., Schweizer, T., Sitarek, J., Šnidarić, I., Sobczynska, D., Somero, A., Stamerra, A., Strzys, M., Surić, T., Tavecchio, F., Temnikov, P., Terzić, T., Teshima, M., Torres-Albà, N., Tsujimoto, S., Vanzo, G., Acosta, M. Vazquez, Vovk, I., Ward, J. E., Will, M., Zarić, D., Raiteri, C. M., Sandrinelli, A., Hovatta, T., Kiehlmann, S., Max-Moerbeck, W., Tornikoski, M., Lähteenmäki, A., Tammi, J., Ramakrishnan, V., Thum, C., Agudo, I., Molina, S. N., Gómez, J. L., Fuentes, A., Casadio, C., Traianou, E., Myserlis, I., and Kim, J. -Y.

Subjects
Astrophysics - Astrophysics of Galaxies
Abstract

PKS 1510-089 is a flat spectrum radio quasar strongly variable in the optical and GeV range. We search for low-state VHE gamma-ray emission from PKS 1510-089. We aim to characterize and model the source in a broad-band context, which would provide a baseline over which high states and flares could be better understood. We use daily binned Fermi-LAT flux measurements of PKS 1510-089 to characterize the GeV emission and select the observation periods of MAGIC during low state of activity. For the selected times we compute the average radio, IR, optical, UV, X-ray and gamma-ray emission to construct a low-state spectral energy distribution of the source. The broadband emission is modelled within an External Compton scenario with a stationary emission region through which plasma and magnetic field are flowing. We perform also the emission-model-independent calculations of the maximum absorption in the broad line region (BLR) using two different models. Results. The MAGIC telescopes collected 75 hrs of data during times when the Fermi-LAT flux measured above 1 GeV was below 3x10-8cm-2s-1, which is the threshold adopted for the definition of a low gamma-ray activity state. The data show a strongly significant (9.5{\sigma}) VHE gamma-ray emission at the level of (4.27+-0.61stat)x10-12cm-2s-1 above 150GeV, a factor 80 smaller than the highest flare observed so far from this object. Despite the lower flux, the spectral shape is consistent with earlier detections in the VHE band. The broad-band emission is compatible with the EC scenario assuming a large emission region located beyond the BLR. For the first time the gamma-ray data allow us to place a limit on the location of the emission region during a low gamma-ray state of a FSRQ. For the used model of the BLR, the 95% C.L. on the location of the emission region allows us to place it at the distance >74% of the outer radius of the BLR., Comment: 12 pages, 7 figures, accepted for publication in A&A

Published
2018
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17. Ordered magnetic fields around the 3C 84 central black hole

Author

Paraschos, G. F., primary, Kim, J.-Y., additional, Wielgus, M., additional, Röder, J., additional, Krichbaum, T. P., additional, Ros, E., additional, Agudo, I., additional, Myserlis, I., additional, Moscibrodzka, M., additional, Traianou, E., additional, Zensus, J. A., additional, Blackburn, L., additional, Chan, C.-K., additional, Issaoun, S., additional, Janssen, M., additional, Johnson, M. D., additional, Fish, V. L., additional, Akiyama, K., additional, Alberdi, A., additional, Alef, W., additional, Algaba, J. C., additional, Anantua, R., additional, Asada, K., additional, Azulay, R., additional, Bach, U., additional, Baczko, A.-K., additional, Ball, D., additional, Baloković, M., additional, Barrett, J., additional, Bauböck, M., additional, Benson, B. A., additional, Bintley, D., additional, Blundell, R., additional, Bouman, K. L., additional, Bower, G. C., additional, Boyce, H., additional, Bremer, M., additional, Brinkerink, C. D., additional, Brissenden, R., additional, Britzen, S., additional, Broderick, A. E., additional, Broguiere, D., additional, Bronzwaer, T., additional, Bustamante, S., additional, Byun, D.-Y., additional, Carlstrom, J. E., additional, Ceccobello, C., additional, Chael, A., additional, Chang, D. O., additional, Chatterjee, K., additional, Chatterjee, S., additional, Chen, M. T., additional, Chen, Y., additional, Cheng, X., additional, Cho, I., additional, Christian, P., additional, Conroy, N. S., additional, Conway, J. E., additional, Cordes, J. M., additional, Crawford, T. M., additional, Crew, G. B., additional, Cruz-Osorio, A., additional, Cui, Y., additional, Dahale, R., additional, Davelaar, J., additional, De Laurentis, M., additional, Deane, R., additional, Dempsey, J., additional, Desvignes, G., additional, Dexter, J., additional, Dhruv, V., additional, Doeleman, S. S., additional, Dougal, S., additional, Dzib, S. A., additional, Eatough, R. P., additional, Emami, R., additional, Falcke, H., additional, Farah, J., additional, Fomalont, E., additional, Ford, H. A., additional, Foschi, M., additional, Fraga-Encinas, R., additional, Freeman, W. T., additional, Friberg, P., additional, Fromm, C. M., additional, Fuentes, A., additional, Galison, P., additional, Gammie, C. F., additional, García, R., additional, Gentaz, O., additional, Georgiev, B., additional, Goddi, C., additional, Gold, R., additional, Gómez-Ruiz, A. I., additional, Gómez, J. L., additional, Gu, M., additional, Gurwell, M., additional, Hada, K., additional, Haggard, D., additional, Haworth, K., additional, Hecht, M. H., additional, Hesper, R., additional, Heumann, D., additional, Ho, L. C., additional, Ho, P., additional, Honma, M., additional, Huang, C. L., additional, Huang, L., additional, Hughes, D. H., additional, Ikeda, S., additional, Impellizzeri, C. M. V., additional, Inoue, M., additional, James, D. J., additional, Jannuzi, B. T., additional, Jeter, B., additional, Jaing, W., additional, Jiménez-Rosales, A., additional, Jorstad, S., additional, Joshi, A. V., additional, Jung, T., additional, Karami, M., additional, Karuppusamy, R., additional, Kawashima, T., additional, Keating, G. K., additional, Kettenis, M., additional, Kim, D.-J., additional, Kim, J., additional, Kino, M., additional, Koay, J. Y., additional, Kocherlakota, P., additional, Kofuji, Y., additional, Koch, P. M., additional, Koyama, S., additional, Kramer, C., additional, Kramer, J. A., additional, Kramer, M., additional, Kuo, C.-Y., additional, La Bella, N., additional, Lauer, T. R., additional, Lee, D., additional, Lee, S.-S., additional, Leung, P. K., additional, Levis, A., additional, Li, Z., additional, Lico, R., additional, Lindahl, G., additional, Lindqvist, M., additional, Lisakov, M., additional, Liu, J., additional, Liu, K., additional, Liuzzo, E., additional, Lo, W.-P., additional, Lobanov, A. P., additional, Loinard, L., additional, Lonsdale, C. J., additional, Lowitz, A. E., additional, Lu, R.-S., additional, MacDonald, N. R., additional, Mao, J., additional, Marchili, N., additional, Markoff, S., additional, Marrone, D. P., additional, Marscher, A. P., additional, Martí-Vidal, I., additional, Matsushita, S., additional, Matthews, L. D., additional, Medeiros, L., additional, Menten, K. M., additional, Michalik, D., additional, Mizuno, I., additional, Mizuno, Y., additional, Moran, J. M., additional, Moriyama, K., additional, Mulaudzi, W., additional, Müller, C., additional, Müller, H., additional, Mus, A., additional, Musoke, G., additional, Nadolski, A., additional, Nagai, H., additional, Nagar, N. M., additional, Nakamura, M., additional, Narayanan, G., additional, Natarajan, I., additional, Nathanail, A., additional, Navarro Fuentes, S., additional, Neilsen, J., additional, Neri, R., additional, Ni, C., additional, Noutsos, A., additional, Nowak, M. A., additional, Oh, J., additional, Okino, H., additional, Olivares, H., additional, Ortiz-León, G. N., additional, Oyama, T., additional, Özel, F., additional, Palumbo, D. C. M., additional, Park, J., additional, Parsons, H., additional, Patel, N., additional, Pen, U.-L., additional, Piétu, V., additional, Plambeck, R., additional, PopStefanija, A., additional, Porth, O., additional, Pötzl, F. M., additional, Prather, B., additional, Preciado-López, J. A., additional, Psaltis, D., additional, Pu, H.-Y., additional, Ramakrishnan, V., additional, Rao, R., additional, Rawlings, M. G., additional, Raymond, A. W., additional, Rezzolla, L., additional, Ricarte, A., additional, Ripperda, B., additional, Roelofs, F., additional, Rogers, A., additional, Romero-Cañizales, C., additional, Roshanineshat, A., additional, Rottmann, H., additional, Roy, A. L., additional, Ruiz, I., additional, Ruszczyk, C., additional, Rygl, K. L. J., additional, Sánchez, S., additional, Sánchez-Argüelles, D., additional, Sánchez-Portal, M., additional, Sasada, M., additional, Satapathy, K., additional, Savolainen, T., additional, Schloerb, F. P., additional, Schonfeld, J., additional, Schuster, K., additional, Shao, L., additional, Shen, Z., additional, Small, D., additional, Sohn, B. W., additional, SooHoo, J., additional, Sosapanta Salas, L. D., additional, Souccar, K., additional, Sun, H., additional, Tazaki, F., additional, Tetarenko, A. J., additional, Tiede, P., additional, Tilanus, R. P. J., additional, Titus, M., additional, Torne, P., additional, Toscano, T., additional, Trent, T., additional, Trippe, S., additional, Turk, M., additional, van Bemmel, I., additional, van Langevelde, H. J., additional, van Rossum, D. R., additional, Vos, J., additional, Wagner, J., additional, Ward-Thompson, D., additional, Wardle, J., additional, Washington, J. E., additional, Weintroub, J., additional, Wharton, R., additional, Wiik, K., additional, Witzel, G., additional, Wondrak, M. F., additional, Wong, G. N., additional, Wu, Q., additional, Yadlapalli, N., additional, Yamaguchi, P., additional, Yfantis, A., additional, Yoon, D., additional, Young, A., additional, Young, K., additional, Younsi, Z., additional, Yu, W., additional, Yuan, F., additional, Yuan, Y.-F., additional, Zhang, S., additional, Zhao, G. Y., additional, and Zhao, S.-S., additional

Published
2024
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18. Multimessenger Characterization of Markarian 501 during Historically Low X-Ray and γ-Ray Activity

Author

Abe, H., primary, Abe, S., additional, Acciari, V. A., additional, Agudo, I., additional, Aniello, T., additional, Ansoldi, S., additional, Antonelli, L. A., additional, Arbet-Engels, A., additional, Arcaro, C., additional, Artero, M., additional, Asano, K., additional, Baack, D., additional, Babić, A., additional, Baquero, A., additional, de Almeida, U. Barres, additional, Barrio, J. A., additional, Batković, I., additional, Baxter, J., additional, Becerra González, J., additional, Bednarek, W., additional, Bernardini, E., additional, Bernardos, M., additional, Berti, A., additional, Besenrieder, J., additional, Bhattacharyya, W., additional, Bigongiari, C., additional, Biland, A., additional, Blanch, O., additional, Bonnoli, G., additional, Bošnjak, Ž., additional, Burelli, I., additional, Busetto, G., additional, Carosi, R., additional, Carretero-Castrillo, M., additional, Castro-Tirado, A. J., additional, Ceribella, G., additional, Chai, Y., additional, Chilingarian, A., additional, Cikota, S., additional, Colombo, E., additional, Contreras, J. L., additional, Cortina, J., additional, Covino, S., additional, D’Amico, G., additional, D’Elia, V., additional, Da Vela, P., additional, Dazzi, F., additional, De Angelis, A., additional, De Lotto, B., additional, Del Popolo, A., additional, Delfino, M., additional, Delgado, J., additional, Delgado Mendez, C., additional, Depaoli, D., additional, Di Pierro, F., additional, Di Venere, L., additional, Souto Espiñeira, E. Do, additional, Dominis Prester, D., additional, Donini, A., additional, Dorner, D., additional, Doro, M., additional, Elsaesser, D., additional, Emery, G., additional, Escudero, J., additional, Fallah Ramazani, V., additional, Fariña, L., additional, Fattorini, A., additional, Foffano, L., additional, Font, L., additional, Fruck, C., additional, Fukami, S., additional, Fukazawa, Y., additional, García López, R. J., additional, Garczarczyk, M., additional, Gasparyan, S., additional, Gaug, M., additional, Giesbrecht Paiva, J. G., additional, Giglietto, N., additional, Giordano, F., additional, Gliwny, P., additional, Godinović, N., additional, Grau, R., additional, Green, D., additional, Green, J. G., additional, Hadasch, D., additional, Hahn, A., additional, Hassan, T., additional, Heckmann, L., additional, Herrera, J., additional, Hrupec, D., additional, Hütten, M., additional, Imazawa, R., additional, Inada, T., additional, Iotov, R., additional, Ishio, K., additional, Jiménez Martínez, I., additional, Jormanainen, J., additional, Kerszberg, D., additional, Kobayashi, Y., additional, Kubo, H., additional, Kushida, J., additional, Lamastra, A., additional, Lelas, D., additional, Leone, F., additional, Lindfors, E., additional, Linhoff, L., additional, Lombardi, S., additional, Longo, F., additional, López-Coto, R., additional, López-Moya, M., additional, López-Oramas, A., additional, Loporchio, S., additional, Lorini, A., additional, Lyard, E., additional, Machado de Oliveira Fraga, B., additional, Majumdar, P., additional, Makariev, M., additional, Maneva, G., additional, Mang, N., additional, Manganaro, M., additional, Mangano, S., additional, Mannheim, K., additional, Mariotti, M., additional, Martínez, M., additional, Mas-Aguilar, A., additional, Mazin, D., additional, Menchiari, S., additional, Mender, S., additional, Mićanović, S., additional, Miceli, D., additional, Miener, T., additional, Miranda, J. M., additional, Mirzoyan, R., additional, Molina, E., additional, Mondal, H. A., additional, Moralejo, A., additional, Morcuende, D., additional, Moreno, V., additional, Nakamori, T., additional, Nanci, C., additional, Nava, L., additional, Neustroev, V., additional, Nievas Rosillo, M., additional, Nigro, C., additional, Nilsson, K., additional, Nishijima, K., additional, Njoh Ekoume, T., additional, Noda, K., additional, Nozaki, S., additional, Ohtani, Y., additional, Oka, T., additional, Okumura, A., additional, Otero-Santos, J., additional, Paiano, S., additional, Palatiello, M., additional, Paneque, D., additional, Paoletti, R., additional, Paredes, J. M., additional, Pavletić, L., additional, Persic, M., additional, Pihet, M., additional, Pirola, G., additional, Podobnik, F., additional, Moroni, P. G. Prada, additional, Prandini, E., additional, Principe, G., additional, Priyadarshi, C., additional, Rhode, W., additional, Ribó, M., additional, Rico, J., additional, Righi, C., additional, Rugliancich, A., additional, Sahakyan, N., additional, Saito, T., additional, Sakurai, S., additional, Satalecka, K., additional, Saturni, F. G., additional, Schleicher, B., additional, Schmidt, K., additional, Schmuckermaier, F., additional, Schubert, J. L., additional, Schweizer, T., additional, Sitarek, J., additional, Sliusar, V., additional, Sobczynska, D., additional, Spolon, A., additional, Stamerra, A., additional, Strišković, J., additional, Strom, D., additional, Strzys, M., additional, Suda, Y., additional, Surić, T., additional, Tajima, H., additional, Takahashi, M., additional, Takeishi, R., additional, Tavecchio, F., additional, Temnikov, P., additional, Terauchi, K., additional, Terzić, T., additional, Teshima, M., additional, Tosti, L., additional, Truzzi, S., additional, Tutone, A., additional, Ubach, S., additional, van Scherpenberg, J., additional, Acosta, M. Vazquez, additional, Ventura, S., additional, Verguilov, V., additional, Viale, I., additional, Vigorito, C. F., additional, Vitale, V., additional, Vovk, I., additional, Walter, R., additional, Will, M., additional, Wunderlich, C., additional, Yamamoto, T., additional, Zarić, D., additional, Cerruti, M., additional, Acosta-Pulido, J. A., additional, Apolonio, G., additional, Bachev, R., additional, Baloković, M., additional, Benítez, E., additional, Björklund, I., additional, Bozhilov, V., additional, Brown, L. F., additional, Bugg, A., additional, Carbonell, W., additional, Carnerero, M. I., additional, Carosati, D., additional, Casadio, C., additional, Chamani, W., additional, Chen, W. P., additional, Chigladze, R. A., additional, Damljanovic, G., additional, Epps, K., additional, Erkenov, A., additional, Feige, M., additional, Finke, J., additional, Fuentes, A., additional, Gazeas, K., additional, Giroletti, M., additional, Grishina, T. S., additional, Gupta, A. C., additional, Gurwell,, M. A., additional, Heidemann, E., additional, Hiriart, D., additional, Hou, W. J., additional, Hovatta, T., additional, Ibryamov, S., additional, Joner, M. D., additional, Jorstad, S. G., additional, Kania, J., additional, Kiehlmann, S., additional, Kimeridze, G. N., additional, Kopatskaya, E. N., additional, Kopp, M., additional, Korte, M., additional, Kotas, B., additional, Koyama, S., additional, Kramer, J. A., additional, Kunkel, L., additional, Kurtanidze, S. O., additional, Kurtanidze, O. M., additional, Lähteenmäki, A., additional, López, J. M., additional, Larionov, V. M., additional, Larionova, E. G., additional, Larionova, L. V., additional, Leto, C., additional, Lorey, C., additional, Mújica, R., additional, Madejski, G. M., additional, Marchili, N., additional, Marscher, A. P., additional, Minev, M., additional, Modaressi, A., additional, Morozova, D. A., additional, Mufakharov, T., additional, Myserlis, I., additional, Nikiforova, A. A., additional, Nikolashvili, M. G., additional, Ovcharov, E., additional, Perri, M., additional, Raiteri, C. M., additional, Readhead, A. C. S., additional, Reimer, A., additional, Reinhart, D., additional, Righini, S., additional, Rosenlehner, K., additional, Sadun, A. C., additional, Savchenko, S. S., additional, Scherbantin, A., additional, Schneider, L., additional, Schoch, K., additional, Seifert, D., additional, Semkov, E., additional, Sigua, L. A., additional, Singh, C., additional, Sola, P., additional, Sotnikova, Y., additional, Spencer, M., additional, Steineke, R., additional, Stojanovic, M., additional, Strigachev, A., additional, Tornikoski, M., additional, Traianou, E., additional, Tramacere, A., additional, Troitskaya, Yu. V., additional, Troitskiy, I. S., additional, Trump, J. B., additional, Tsai, A., additional, Valcheva, A., additional, Vasilyev, A. A., additional, Verrecchia, F., additional, Villata, M., additional, Vince, O., additional, Vrontaki, K., additional, Weaver, Z. R., additional, Zaharieva, E., additional, and Zottmann, N., additional

Published
2023
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19. A ring-like accretion structure in M87 connecting its black hole and jet

Author

Ministerio de Ciencia e Innovación (España), European Commission, European Research Council, Natural Sciences and Engineering Research Council of Canada, National Natural Science Foundation of China, Ministry of Science, ICT and Future Planning (South Korea), Ministry of Education, Culture, Sports, Science and Technology (Japan), National Research Foundation of Korea, Lu, Ru-Sen, Gómez, José L., Traianou, E., Yu, Chen-Yu, Ministerio de Ciencia e Innovación (España), European Commission, European Research Council, Natural Sciences and Engineering Research Council of Canada, National Natural Science Foundation of China, Ministry of Science, ICT and Future Planning (South Korea), Ministry of Education, Culture, Sports, Science and Technology (Japan), National Research Foundation of Korea, Lu, Ru-Sen, Gómez, José L., Traianou, E., and Yu, Chen-Yu

Abstract

The nearby radio galaxy M87 is a prime target for studying black hole accretion and jet formation1,2. Event Horizon Telescope observations of M87 in 2017, at a wavelength of 1.3 mm, revealed a ring-like structure, which was interpreted as gravitationally lensed emission around a central black hole3. Here we report images of M87 obtained in 2018, at a wavelength of 3.5 mm, showing that the compact radio core is spatially resolved. High-resolution imaging shows a ring-like structure of 8.4+0.5−1.1 Schwarzschild radii in diameter, approximately 50% larger than that seen at 1.3 mm. The outer edge at 3.5 mm is also larger than that at 1.3 mm. This larger and thicker ring indicates a substantial contribution from the accretion flow with absorption effects, in addition to the gravitationally lensed ring-like emission. The images show that the edge-brightened jet connects to the accretion flow of the black hole. Close to the black hole, the emission profile of the jet-launching region is wider than the expected profile of a black-hole-driven jet, suggesting the possible presence of a wind associated with the accretion flow. © The Author(s) 2023.

Published
2023

20. Accretion Flow Morphology in Numerical Simulations of Black Holes from the ngEHT Model Library: The Impact of Radiation Physics

Author

Ministerio de Ciencia e Innovación (España), European Commission, European Research Council, National Science Foundation (US), Gordon and Betty Moore Foundation, International Max Planck Research Schools, German Research Foundation, Chatterjee, Koushik, Chael, Andrew, Tiede, Paul, Mizuno, Yosuke, Emami, Razieh, Fromm, Christian, Ricarte, Angelo, Blackburn, Lindy, Roelofs, Freek, Johnson, Michael D., Doeleman, Sheperd S., Arras, Philipp, Fuentes, Antonio, Knollmüller, Jakob, Kosogorov, Nikita, Lindahl, Greg, Müller, Hendrik, Patel, Nimesh, Raymond, Alexander, Traianou, E., Vega, Justin, Ministerio de Ciencia e Innovación (España), European Commission, European Research Council, National Science Foundation (US), Gordon and Betty Moore Foundation, International Max Planck Research Schools, German Research Foundation, Chatterjee, Koushik, Chael, Andrew, Tiede, Paul, Mizuno, Yosuke, Emami, Razieh, Fromm, Christian, Ricarte, Angelo, Blackburn, Lindy, Roelofs, Freek, Johnson, Michael D., Doeleman, Sheperd S., Arras, Philipp, Fuentes, Antonio, Knollmüller, Jakob, Kosogorov, Nikita, Lindahl, Greg, Müller, Hendrik, Patel, Nimesh, Raymond, Alexander, Traianou, E., and Vega, Justin

Abstract

In the past few years, the Event Horizon Telescope (EHT) has provided the first-ever event horizon-scale images of the supermassive black holes (BHs) M87∗ and Sagittarius A∗ (Sgr A∗ ). The next-generation EHT project is an extension of the EHT array that promises larger angular resolution and higher sensitivity to the dim, extended flux around the central ring-like structure, possibly connecting the accretion flow and the jet. The ngEHT Analysis Challenges aim to understand the science extractability from synthetic images and movies to inform the ngEHT array design and analysis algorithm development. In this work, we compare the accretion flow structure and dynamics in numerical fluid simulations that specifically target M87∗ and Sgr A∗, and were used to construct the source models in the challenge set. We consider (1) a steady-state axisymmetric radiatively inefficient accretion flow model with a time-dependent shearing hotspot, (2) two time-dependent single fluid general relativistic magnetohydrodynamic (GRMHD) simulations from the H-AMR code, (3) a two-temperature GRMHD simulation from the BHAC code, and (4) a two-temperature radiative GRMHD simulation from the KORAL code. We find that the different models exhibit remarkably similar temporal and spatial properties, except for the electron temperature, since radiative losses substantially cool down electrons near the BH and the jet sheath, signaling the importance of radiative cooling even for slowly accreting BHs such as M87∗. We restrict ourselves to standard torus accretion flows, and leave larger explorations of alternate accretion models to future work. © 2023 by the authors. Licensee MDPI, Basel, Switzerland.

Published
2023

21. The ngEHT Analysis Challenges

Author

Ministerio de Ciencia e Innovación (España), European Research Council, European Commission, Gordon and Betty Moore Foundation, Roelofs, Freek, Blackburn, Lindy, Lindahl, Greg, Doeleman, Sheperd S., Johnson, Michael D., Arras, Philipp, Chatterjee, Koushik, Emami, Razieh, Fromm, Christian, Fuentes, Antonio, Knollmüller, Jakob, Kosogorov, Nikita, Müller, Hendrik, Patel, Nimesh, Raymond, Alexander W., Tiede, Paul, Traianou, E., Vega, Justin, Ministerio de Ciencia e Innovación (España), European Research Council, European Commission, Gordon and Betty Moore Foundation, Roelofs, Freek, Blackburn, Lindy, Lindahl, Greg, Doeleman, Sheperd S., Johnson, Michael D., Arras, Philipp, Chatterjee, Koushik, Emami, Razieh, Fromm, Christian, Fuentes, Antonio, Knollmüller, Jakob, Kosogorov, Nikita, Müller, Hendrik, Patel, Nimesh, Raymond, Alexander W., Tiede, Paul, Traianou, E., and Vega, Justin

Abstract

The next-generation Event Horizon Telescope (ngEHT) will be a significant enhancement of the Event Horizon Telescope (EHT) array, with ∼10 new antennas and instrumental upgrades of existing antennas. The increased -coverage, sensitivity, and frequency coverage allow a wide range of new science opportunities to be explored. The ngEHT Analysis Challenges have been launched to inform the development of the ngEHT array design, science objectives, and analysis pathways. For each challenge, synthetic EHT and ngEHT datasets are generated from theoretical source models and released to the challenge participants, who analyze the datasets using image reconstruction and other methods. The submitted analysis results are evaluated with quantitative metrics. In this work, we report on the first two ngEHT Analysis Challenges. These have focused on static and dynamical models of M87* and Sgr A* and shown that high-quality movies of the extended jet structure of M87* and near-horizon hourly timescale variability of Sgr A* can be reconstructed by the reference ngEHT array in realistic observing conditions using current analysis algorithms. We identify areas where there is still room for improvement of these algorithms and analysis strategies. Other science cases and arrays will be explored in future challenges. © 2023 by the authors. Licensee MDPI, Basel, Switzerland.

Published
2023

22. Multi-Wavelength and Multi-Messenger Studies Using the Next-Generation Event Horizon Telescope

Author

Ministerio de Ciencia e Innovación (España), Junta de Andalucía, European Commission, National Aeronautics and Space Administration (US), Lico, Rocco, Jorstad, Svetlana G., Marscher, Alan P., Gómez, José L., Liodakis, Ioannis, Dahale, Rohan, Alberdi, Antxón, Gold, Roman, Traianou, E., Toscano, Teresa, Foschi, Marianna, Ministerio de Ciencia e Innovación (España), Junta de Andalucía, European Commission, National Aeronautics and Space Administration (US), Lico, Rocco, Jorstad, Svetlana G., Marscher, Alan P., Gómez, José L., Liodakis, Ioannis, Dahale, Rohan, Alberdi, Antxón, Gold, Roman, Traianou, E., Toscano, Teresa, and Foschi, Marianna

Abstract

The next-generation Event Horizon Telescope (ngEHT) will provide us with the best opportunity to investigate supermassive black holes (SMBHs) at the highest possible resolution and sensitivity. With respect to the existing Event Horizon Telescope (EHT) array, the ngEHT will provide increased sensitivity and uv-coverage (with the addition of new stations), wider frequency coverage (from 86 GHz to 345 GHz and higher), finer resolution (<15 micro-arcseconds), and better monitoring capabilities. The ngEHT will offer a unique opportunity to deeply investigate the physics around SMBHs, such as the disk-jet connection, the mechanisms responsible for high-energy photon and neutrino events, and the role of magnetic fields in shaping relativistic jets, as well as the nature of binary SMBH systems. In this white paper we describe some ngEHT science cases in the context of multi-wavelength studies and synergies. © 2023 by the authors. Licensee MDPI, Basel, Switzerland.

Published
2023

23. Comparison of Polarized Radiative Transfer Codes Used by the EHT Collaboration

Author

Ministerio de Ciencia e Innovación (España), Agencia Estatal de Investigación (España), Prather, Ben S., Alberdi, Antxón, Cho, I., Fuentes, Antonio, Gómez, José L., Lico, Rocco, Traianou, E., Zhao, Guang-Yao, Event Horizon Telescope, Ministerio de Ciencia e Innovación (España), Agencia Estatal de Investigación (España), Prather, Ben S., Alberdi, Antxón, Cho, I., Fuentes, Antonio, Gómez, José L., Lico, Rocco, Traianou, E., Zhao, Guang-Yao, and Event Horizon Telescope

Abstract

Interpretation of resolved polarized images of black holes by the Event Horizon Telescope (EHT) requires predictions of the polarized emission observable by an Earth-based instrument for a particular model of the black hole accretion system. Such predictions are generated by general relativistic radiative transfer (GRRT) codes, which integrate the equations of polarized radiative transfer in curved spacetime. A selection of ray-tracing GRRT codes used within the EHT Collaboration is evaluated for accuracy and consistency in producing a selection of test images, demonstrating that the various methods and implementations of radiative transfer calculations are highly consistent. When imaging an analytic accretion model, we find that all codes produce images similar within a pixel-wise normalized mean squared error (NMSE) of 0.012 in the worst case. When imaging a snapshot from a cell-based magnetohydrodynamic simulation, we find all test images to be similar within NMSEs of 0.02, 0.04, 0.04, and 0.12 in Stokes I, Q, U, and V, respectively. We additionally find the values of several image metrics relevant to published EHT results to be in agreement to much better precision than measurement uncertainties. © 2023. The Author(s). Published by the American Astronomical Society.

Published
2023

24. First M87 Event Horizon Telescope Results. IX. Detection of Near-horizon Circular Polarization

Author

European Research Council, Ministerio de Ciencia e Innovación (España), European Commission, Event Horizon Telescope Collaboration, Alberdi, Antxón, Cho, I., Dahale, Rohan, Foschi, Marianna, Fuentes, Antonio, Gómez, José L., Lico, Rocco, Traianou, E., Toscano, Teresa, Zhao, Guang-Yao, European Research Council, Ministerio de Ciencia e Innovación (España), European Commission, Event Horizon Telescope Collaboration, Alberdi, Antxón, Cho, I., Dahale, Rohan, Foschi, Marianna, Fuentes, Antonio, Gómez, José L., Lico, Rocco, Traianou, E., Toscano, Teresa, and Zhao, Guang-Yao

Abstract

Event Horizon Telescope (EHT) observations have revealed a bright ring of emission around the supermassive black hole at the center of the M87 galaxy. EHT images in linear polarization have further identified a coherent spiral pattern around the black hole, produced from ordered magnetic fields threading the emitting plasma. Here we present the first analysis of circular polarization using EHT data, acquired in 2017, which can potentially provide additional insights into the magnetic fields and plasma composition near the black hole. Interferometric closure quantities provide convincing evidence for the presence of circularly polarized emission on event-horizon scales. We produce images of the circular polarization using both traditional and newly developed methods. All methods find a moderate level of resolved circular polarization across the image (divided by v divided by > < 3.7%), consistent with the low image-integrated circular polarization fraction measured by the Atacama Large Millimeter/submillimeter Array (divided by v(int)divided by < 1%). Despite this broad agreement, the methods show substantial variation in the morphology of the circularly polarized emission, indicating that our conclusions are strongly dependent on the imaging assumptions because of the limited baseline coverage, uncertain telescope gain calibration, and weakly polarized signal. We include this upper limit in an updated comparison to general relativistic magnetohydrodynamic simulation models. This analysis reinforces the previously reported preference for magnetically arrested accretion flow models. We find that most simulations naturally produce a low level of circular polarization consistent with our upper limit and that Faraday conversion is likely the dominant production mechanism for circular polarization at 230 GHz in M87*. © . The Author(s). Published by the American Astronomical Society.

Published
2023

25. Filamentary structures as the origin of blazar jet radio variability

Author

Ministerio de Economía y Competitividad (España), Junta de Andalucía, Consejo Superior de Investigaciones Científicas (España), Agencia Estatal de Investigación (España), Generalitat Valenciana, National Research Foundation of Korea, National Natural Science Foundation of China, Academy of Finland, Russian Science Foundation, Fuentes, Antonio, Gómez, José L., Zhao, Guang-Yao, Lico, Rocco, Cho, I., Traianou, E., Toscano, Teresa, Dahale, Rohan, Foschi, Marianna, Ministerio de Economía y Competitividad (España), Junta de Andalucía, Consejo Superior de Investigaciones Científicas (España), Agencia Estatal de Investigación (España), Generalitat Valenciana, National Research Foundation of Korea, National Natural Science Foundation of China, Academy of Finland, Russian Science Foundation, Fuentes, Antonio, Gómez, José L., Zhao, Guang-Yao, Lico, Rocco, Cho, I., Traianou, E., Toscano, Teresa, Dahale, Rohan, and Foschi, Marianna

Abstract

Supermassive black holes at the centre of active galactic nuclei power some of the most luminous objects in the Universe. Typically, very-long-baseline interferometric observations of blazars have revealed only funnel-like morphologies with little information on the internal structure of the ejected plasma or have lacked the dynamic range to reconstruct the extended jet emission. Here we present microarcsecond-scale angular resolution images of the blazar 3C 279 obtained at 22 GHz with the space very-long-baseline interferometry mission RadioAstron, which allowed us to resolve the jet transversely and reveal several filaments produced by plasma instabilities in a kinetically dominated flow. The polarimetric properties derived from our high-angular-resolution and broad-dynamic-range images are consistent with the presence of a helical magnetic field threaded to the jet. We infer a clockwise rotation as seen in the direction of flow motion with an intrinsic helix pitch angle of ~45° and a Lorentz factor of ~13 at the time of observation. We also propose a model to explain blazar jet radio variability in which emission features travelling down the jet may manifest as a result of differential Doppler boosting within the filaments, as opposed to the standard shock-in-jet model. Characterizing such variability is particularly important given the relevance of blazar physics from cosmic particle acceleration to standard candles in cosmology. © 2023, The Author(s), under exclusive licence to Springer Nature Limited.

Published
2023

26. Repeating flaring activity of the blazar AO 0235+164.

Author

Escudero Pedrosa, J., Agudo, I., Tramacere, A., Marscher, A. P., Jorstad, S., Weaver, Z. R., Casadio, C., Thum, C., Myserlis, I., Fuentes, A., Traianou, E., Kim, J.-Y., Kramer, J., López-Coto, R., D'Ammando, F., Bernardos, M., Bonnoli, G., Blinov, D. A., Borman, G. A., and Grishina, T. S.

Subjects
SPECTRAL energy distribution, STATISTICAL correlation, X-ray spectra, IMAGE analysis
Abstract

Context. Blazar AO 0235+164, located at a redshift of z = 0.94, has undergone several sharp multi-spectral-range flaring episodes over recent decades. In particular, the episodes that peaked in 2008 and 2015, which were subject to extensive multi-wavelength coverage, exhibited an interesting behavior. Aims. We study the actual origin of these two observed flares by constraining the properties of the observed photo-polarimetric variability as well as of the broadband spectral energy distribution and the observed time-evolution behavior of the source. We use ultra-high-resolution total-flux and polarimetric very-long-baseline interferometry (VLBI) imaging. Methods. The analysis of VLBI images allowed us to constrain kinematic and geometrical parameters of the 7 mm jet. We used the discrete correlation function to compute the statistical correlation and the delays between emission at different spectral ranges. The multi-epoch modeling of the spectral energy distributions allowed us to propose specific models of the emission; in particular, with the aim to model the unusual spectral features observed in this source in the X-ray region of the spectrum during strong multi spectral-range flares. Results. We find that these X-ray spectral features can be explained by an emission component originating in a separate particle distribution than the one responsible for the two standard blazar bumps. This is in agreement with the results of our correlation analysis, where we did not find a strong correlation between the X-ray and the remaining spectral ranges. We find that both external Compton-dominated and synchrotron self-Compton-dominated models are able to explain the observed spectral energy distributions. However, the synchrotron self-Compton models are strongly favored by the delays and geometrical parameters inferred from the observations. [ABSTRACT FROM AUTHOR]

Published
2024
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27. Resolving the Inner Parsec of the Blazar J1924–2914 with the Event Horizon Telescope

Author

Issaoun, S. Wielgus, M. Jorstad, S. Krichbaum, T.P. Blackburn, L. Janssen, M. Chan, C.-K. Pesce, D.W. Gómez, J.L. Akiyama, K. Moscibrodzka, M. Martí-Vidal, I. Chael, A. Lico, R. Ramakrishnan, V. Liu, J. Lisakov, M. Fuentes, A. Zhao, G.-Y. Moriyama, K. Broderick, A.E. Tiede, P. MacDonald, N.R. Gao, M. Traianou, E. Loinard, L. Davelaar, J. Gurwell, M. Lu, R.-S. Alberdi, A. Alef, W. Algaba, J.C. Anantua, R. Asada, K. Azulay, R. Baczko, A.-K. Ball, D. Balokovic, M. Barrett, J. Bauböck, M. Benson, B.A. Bach, U. Bintley, D. Blundell, R. Boland, W. Bouman, K.L. Bower, G.C. Boyce, H. Bremer, M. Brinkerink, C.D. Brissenden, R. Britzen, S. Broguiere, D. Bronzwaer, T. Bustamante, S. Byun, D.-Y. Carlstrom, J.E. Ceccobello, C. Chatterjee, K. Chatterjee, S. Chen, M.-T. Chen, Y. Cho, I. Christian, P. Conroy, N.S. Conway, J.E. Cordes, J.M. Crawford, T.M. Crew, G.B. Cruz-Osorio, A. Cui, Y. De Laurentis, M. Deane, R. Dempsey, J. Desvignes, G. Dexter, J. Doeleman, S.S. Dhruv, V. Dzib Quijano, S.A. Eatough, R.P. Emami, R. Falcke, H. Farah, J. Fish, V.L. Fomalont, E. Alyson Ford, H. Fraga-Encinas, R. Freeman, W.T. Friberg, P. Fromm, C.M. Galison, P. Gammie, C.F. García, R. Gentaz, O. Georgiev, B. Goddi, C. Gold, R. Gómez-Ruiz, A.I. Gu, M. Hada, K. Haggard, D. Hesper, R. Ho, L.C. Hecht, M.H. Ho, P. Honma, M. Huang, C.-W.L. Huang, L. Hughes, D.H. Ikeda, S. Impellizzeri, C.M.V. Inoue, M. James, D.J. Jannuzi, B.T. Jeter, B. Jiang, W. Jimenez-Rosales, A. Johnson, M.D. Joshi, A.V. Jung, T. Karami, M. Karuppusamy, R. Kawashima, T. Keating, G.K. Kettenis, M. Kim, D.-J. Kim, J.-Y. Kim, J. Kim, J. Kino, M. Yi Koay, J. Kocherlakota, P. Kofuji, Y. Koch, P.M. Koyama, S. Kramer, C. Kramer, M. Kuo, C.-Y. Lauer, T.R. Lee, D. Lee, S.-S. Leung, P.K. Levis, A. Li, Z. Bella, N.L. Lico, R. Lindahl, G. Lindqvist, M. Liu, K. Liuzzo, E. Lo, W.-P. Lobanov, A.P. Lonsdale, C. Mao, J. Marchili, N. Markoff, S. Marrone, D.P. Marscher, A.P. Matsushita, S. Matthews, L.D. Medeiros, L. Menten, K.M. Michalik, D. Mizuno and Issaoun, S. Wielgus, M. Jorstad, S. Krichbaum, T.P. Blackburn, L. Janssen, M. Chan, C.-K. Pesce, D.W. Gómez, J.L. Akiyama, K. Moscibrodzka, M. Martí-Vidal, I. Chael, A. Lico, R. Ramakrishnan, V. Liu, J. Lisakov, M. Fuentes, A. Zhao, G.-Y. Moriyama, K. Broderick, A.E. Tiede, P. MacDonald, N.R. Gao, M. Traianou, E. Loinard, L. Davelaar, J. Gurwell, M. Lu, R.-S. Alberdi, A. Alef, W. Algaba, J.C. Anantua, R. Asada, K. Azulay, R. Baczko, A.-K. Ball, D. Balokovic, M. Barrett, J. Bauböck, M. Benson, B.A. Bach, U. Bintley, D. Blundell, R. Boland, W. Bouman, K.L. Bower, G.C. Boyce, H. Bremer, M. Brinkerink, C.D. Brissenden, R. Britzen, S. Broguiere, D. Bronzwaer, T. Bustamante, S. Byun, D.-Y. Carlstrom, J.E. Ceccobello, C. Chatterjee, K. Chatterjee, S. Chen, M.-T. Chen, Y. Cho, I. Christian, P. Conroy, N.S. Conway, J.E. Cordes, J.M. Crawford, T.M. Crew, G.B. Cruz-Osorio, A. Cui, Y. De Laurentis, M. Deane, R. Dempsey, J. Desvignes, G. Dexter, J. Doeleman, S.S. Dhruv, V. Dzib Quijano, S.A. Eatough, R.P. Emami, R. Falcke, H. Farah, J. Fish, V.L. Fomalont, E. Alyson Ford, H. Fraga-Encinas, R. Freeman, W.T. Friberg, P. Fromm, C.M. Galison, P. Gammie, C.F. García, R. Gentaz, O. Georgiev, B. Goddi, C. Gold, R. Gómez-Ruiz, A.I. Gu, M. Hada, K. Haggard, D. Hesper, R. Ho, L.C. Hecht, M.H. Ho, P. Honma, M. Huang, C.-W.L. Huang, L. Hughes, D.H. Ikeda, S. Impellizzeri, C.M.V. Inoue, M. James, D.J. Jannuzi, B.T. Jeter, B. Jiang, W. Jimenez-Rosales, A. Johnson, M.D. Joshi, A.V. Jung, T. Karami, M. Karuppusamy, R. Kawashima, T. Keating, G.K. Kettenis, M. Kim, D.-J. Kim, J.-Y. Kim, J. Kim, J. Kino, M. Yi Koay, J. Kocherlakota, P. Kofuji, Y. Koch, P.M. Koyama, S. Kramer, C. Kramer, M. Kuo, C.-Y. Lauer, T.R. Lee, D. Lee, S.-S. Leung, P.K. Levis, A. Li, Z. Bella, N.L. Lico, R. Lindahl, G. Lindqvist, M. Liu, K. Liuzzo, E. Lo, W.-P. Lobanov, A.P. Lonsdale, C. Mao, J. Marchili, N. Markoff, S. Marrone, D.P. Marscher, A.P. Matsushita, S. Matthews, L.D. Medeiros, L. Menten, K.M. Michalik, D. Mizuno

Abstract

The blazar J1924–2914 is a primary Event Horizon Telescope (EHT) calibrator for the Galactic center’s black hole Sagittarius A*. Here we present the first total and linearly polarized intensity images of this source obtained with the unprecedented 20 µas resolution of the EHT. J1924–2914 is a very compact flat-spectrum radio source with strong optical variability and polarization. In April 2017 the source was observed quasi-simultaneously with the EHT (April 5–11), the Global Millimeter VLBI Array (April 3), and the Very Long Baseline Array (April 28), giving a novel view of the source at four observing frequencies, 230, 86, 8.7, and 2.3 GHz. These observations probe jet properties from the subparsec to 100 pc scales. We combine the multifrequency images of J1924–2914 to study the source morphology. We find that the jet exhibits a characteristic bending, with a gradual clockwise rotation of the jet projected position angle of about 90° between 2.3 and 230 GHz. Linearly polarized intensity images of J1924–2914 with the extremely fine resolution of the EHT provide evidence for ordered toroidal magnetic fields in the blazar compact core. © 2022. The Author(s). Published by the American Astronomical Society.

Published
2022

28. Selective Dynamical Imaging of Interferometric Data

Author

Ministerio de Ciencia e Innovación (España), European Commission, European Research Council, National Science Foundation (US), Gordon and Betty Moore Foundation, Farah, Joseph, Fuentes, Antonio, Gómez, José L., Zhao, Guang-Yao, Alberdi, Antxón, Cho, I., Lico, Rocco, Traianou, E., Zhao, Shan-Shan, Event Horizon Telescope Collaboration, Ministerio de Ciencia e Innovación (España), European Commission, European Research Council, National Science Foundation (US), Gordon and Betty Moore Foundation, Farah, Joseph, Fuentes, Antonio, Gómez, José L., Zhao, Guang-Yao, Alberdi, Antxón, Cho, I., Lico, Rocco, Traianou, E., Zhao, Shan-Shan, and Event Horizon Telescope Collaboration

Abstract

Recent developments in very long baseline interferometry (VLBI) have made it possible for the Event Horizon Telescope (EHT) to resolve the innermost accretion flows of the largest supermassive black holes on the sky. The sparse nature of the EHT's (u, v)-coverage presents a challenge when attempting to resolve highly time-variable sources. We demonstrate that the changing (u, v)-coverage of the EHT can contain regions of time over the course of a single observation that facilitate dynamical imaging. These optimal time regions typically have projected baseline distributions that are approximately angularly isotropic and radially homogeneous. We derive a metric of coverage quality based on baseline isotropy and density that is capable of ranking array configurations by their ability to produce accurate dynamical reconstructions. We compare this metric to existing metrics in the literature and investigate their utility by performing dynamical reconstructions on synthetic data from simulated EHT observations of sources with simple orbital variability. We then use these results to make recommendations for imaging the 2017 EHT Sgr A* data set. © 2022. The Author(s). Published by the American Astronomical Society.

Published
2022

29. Millimeter Light Curves of Sagittarius A* Observed during the 2017 Event Horizon Telescope Campaign

Author

Ministerio de Ciencia e Innovación (España), European Commission, European Research Council, Wielgus, Maciek, Alberdi, Antxón, Cho, I., Fuentes, Antonio, Gómez, José L., Lico, Rocco, Traianou, E., Zhao, Guang-Yao, Zhao, Shan-Shan, Ministerio de Ciencia e Innovación (España), European Commission, European Research Council, Wielgus, Maciek, Alberdi, Antxón, Cho, I., Fuentes, Antonio, Gómez, José L., Lico, Rocco, Traianou, E., Zhao, Guang-Yao, and Zhao, Shan-Shan

Abstract

The Event Horizon Telescope (EHT) observed the compact radio source, Sagittarius A* (Sgr A*), in the Galactic Center on 2017 April 5–11 in the 1.3 mm wavelength band. At the same time, interferometric array data from the Atacama Large Millimeter/submillimeter Array and the Submillimeter Array were collected, providing Sgr A* light curves simultaneous with the EHT observations. These data sets, complementing the EHT very long baseline interferometry, are characterized by a cadence and signal-to-noise ratio previously unattainable for Sgr A* at millimeter wavelengths, and they allow for the investigation of source variability on timescales as short as a minute. While most of the light curves correspond to a low variability state of Sgr A*, the April 11 observations follow an X-ray flare and exhibit strongly enhanced variability. All of the light curves are consistent with a red-noise process, with a power spectral density (PSD) slope measured to be between −2 and −3 on timescales between 1 minute and several hours. Our results indicate a steepening of the PSD slope for timescales shorter than 0.3 hr. The spectral energy distribution is flat at 220 GHz, and there are no time lags between the 213 and 229 GHz frequency bands, suggesting low optical depth for the event horizon scale source. We characterize Sgr A*'s variability, highlighting the different behavior observed just after the X-ray flare, and use Gaussian process modeling to extract a decorrelation timescale and a PSD slope. We also investigate the systematic calibration uncertainties by analyzing data from independent data reduction pipelines. © 2022. The Author(s). Published by the American Astronomical Society.

Published
2022

30. A Universal Power-law Prescription for Variability from Synthetic Images of Black Hole Accretion Flows

Author

Ministerio de Ciencia e Innovación (España), European Commission, European Research Council, Georgiev, Boris, Alberdi, Antxón, Cho, I., Fuentes, Antonio, Gómez, José L., Lico, Rocco, Traianou, E., Zhao, Guang-Yao, Zhao, Shan-Shan, Ministerio de Ciencia e Innovación (España), European Commission, European Research Council, Georgiev, Boris, Alberdi, Antxón, Cho, I., Fuentes, Antonio, Gómez, José L., Lico, Rocco, Traianou, E., Zhao, Guang-Yao, and Zhao, Shan-Shan

Abstract

We present a framework for characterizing the spatiotemporal power spectrum of the variability expected from the horizon-scale emission structure around supermassive black holes, and we apply this framework to a library of general relativistic magnetohydrodynamic (GRMHD) simulations and associated general relativistic ray-traced images relevant for Event Horizon Telescope (EHT) observations of Sgr A*. We find that the variability power spectrum is generically a red-noise process in both the temporal and spatial dimensions, with the peak in power occurring on the longest timescales and largest spatial scales. When both the time-averaged source structure and the spatially integrated light-curve variability are removed, the residual power spectrum exhibits a universal broken power-law behavior. On small spatial frequencies, the residual power spectrum rises as the square of the spatial frequency and is proportional to the variance in the centroid of emission. Beyond some peak in variability power, the residual power spectrum falls as that of the time-averaged source structure, which is similar across simulations; this behavior can be naturally explained if the variability arises from a multiplicative random field that has a steeper high-frequency power-law index than that of the time-averaged source structure. We briefly explore the ability of power spectral variability studies to constrain physical parameters relevant for the GRMHD simulations, which can be scaled to provide predictions for black holes in a range of systems in the optically thin regime. We present specific expectations for the behavior of the M87* and Sgr A* accretion flows as observed by the EHT. © 2022. The Author(s). Published by the American Astronomical Society.

Published
2022

31. First Sagittarius A* Event Horizon Telescope Results. VI. Testing the Black Hole Metric

Author

Ministerio de Ciencia e Innovación (España), European Commission, European Research Council, Swedish Research Council, Science and Technology Facilities Council (UK), Akiyama, Kazunori, Alberdi, Antxón, Cho, I., Fuentes, Antonio, Gómez, José L., Lico, Rocco, Traianou, E., Zhao, Guang-Yao, Zhao, Shan-Shan, Event Horizon Telescope Collaboration, Ministerio de Ciencia e Innovación (España), European Commission, European Research Council, Swedish Research Council, Science and Technology Facilities Council (UK), Akiyama, Kazunori, Alberdi, Antxón, Cho, I., Fuentes, Antonio, Gómez, José L., Lico, Rocco, Traianou, E., Zhao, Guang-Yao, Zhao, Shan-Shan, and Event Horizon Telescope Collaboration

Abstract

Astrophysical black holes are expected to be described by the Kerr metric. This is the only stationary, vacuum, axisymmetric metric, without electromagnetic charge, that satisfies Einstein's equations and does not have pathologies outside of the event horizon. We present new constraints on potential deviations from the Kerr prediction based on 2017 EHT observations of Sagittarius A* (Sgr A*). We calibrate the relationship between the geometrically defined black hole shadow and the observed size of the ring-like images using a library that includes both Kerr and non-Kerr simulations. We use the exquisite prior constraints on the mass-to-distance ratio for Sgr A* to show that the observed image size is within ∼10% of the Kerr predictions. We use these bounds to constrain metrics that are parametrically different from Kerr, as well as the charges of several known spacetimes. To consider alternatives to the presence of an event horizon, we explore the possibility that Sgr A* is a compact object with a surface that either absorbs and thermally reemits incident radiation or partially reflects it. Using the observed image size and the broadband spectrum of Sgr A*, we conclude that a thermal surface can be ruled out and a fully reflective one is unlikely. We compare our results to the broader landscape of gravitational tests. Together with the bounds found for stellar-mass black holes and the M87 black hole, our observations provide further support that the external spacetimes of all black holes are described by the Kerr metric, independent of their mass. © 2022. The Author(s). Published by the American Astronomical Society.

Published
2022

32. Characterizing and Mitigating Intraday Variability: Reconstructing Source Structure in Accreting Black Holes with mm-VLBI

Author

Ministerio de Ciencia e Innovación (España), European Commission, European Research Council, Broderick, Avery E., Alberdi, Antxón, Cho, I., Fuentes, Antonio, Gómez, José L., Lico, Rocco, Traianou, E., Zhao, Guang-Yao, Zhao, Shan-Shan, Ministerio de Ciencia e Innovación (España), European Commission, European Research Council, Broderick, Avery E., Alberdi, Antxón, Cho, I., Fuentes, Antonio, Gómez, José L., Lico, Rocco, Traianou, E., Zhao, Guang-Yao, and Zhao, Shan-Shan

Abstract

The extraordinary physical resolution afforded by the Event Horizon Telescope has opened a window onto the astrophysical phenomena unfolding on horizon scales in two known black holes, M87* and Sgr A*. However, with this leap in resolution has come a new set of practical complications. Sgr A* exhibits intraday variability that violates the assumptions underlying Earth aperture synthesis, limiting traditional image reconstruction methods to short timescales and data sets with very sparse (u, v) coverage. We present a new set of tools to detect and mitigate this variability. We develop a data-driven, model-agnostic procedure to detect and characterize the spatial structure of intraday variability. This method is calibrated against a large set of mock data sets, producing an empirical estimator of the spatial power spectrum of the brightness fluctuations. We present a novel Bayesian noise modeling algorithm that simultaneously reconstructs an average image and statistical measure of the fluctuations about it using a parameterized form for the excess variance in the complex visibilities not otherwise explained by the statistical errors. These methods are validated using a variety of simulated data, including general relativistic magnetohydrodynamic simulations appropriate for Sgr A* and M87*. We find that the reconstructed source structure and variability are robust to changes in the underlying image model. We apply these methods to the 2017 EHT observations of M87*, finding evidence for variability across the EHT observing campaign. The variability mitigation strategies presented are widely applicable to very long baseline interferometry observations of variable sources generally, for which they provide a data-informed averaging procedure and natural characterization of inter-epoch image consistency. © 2022. The Author(s). Published by the American Astronomical Society.

Published
2022

33. Multiwavelength Observations of the Blazar VER J0521+211 during an Elevated TeV Gamma-Ray State

Author

Abe, H., Abe, S., Acciari, V. A., Agudo, I., Aniello, T., Ansoldi, S., Antonelli, L. A., Arbet Engels, A., Arcaro, C., Artero, M., Asano, K., Baack, D., Babić, A., Baquero, A., Barres de Almeida, U., Barrio, J. A., Batković, I., Baxter, J., Becerra González, J., Bednarek, W., Bernardini, E., Bernardos, M., Berti, A., Besenrieder, J., Bhattacharyya, W., Bigongiari, C., Biland, A., Blanch, O., Bonnoli, G., Bošnjak, Ž., Burelli, I., Busetto, G., Carosi, R., Carretero-Castrillo, M., Castro-Tirado, A. J., Ceribella, G., Chai, Y., Chilingarian, A., Cikota, S., Colombo, E., Contreras, J. L., Cortina, J., Covino, S., D'Amico, G., D'Elia, V., Da Vela, P., Dazzi, F., De Angelis, A., De Lotto, B., Del Popolo, A., Delfino, M., Delgado, J., Delgado Mendez, C., Depaoli, D., Di Pierro, F., Di Venere, L., Do Souto Espiñeira, E., Dominis Prester, D., Donini, A., Dorner, D., Doro, M., Elsaesser, D., Emery, G., Escudero, J., Fallah Ramazani, V., Fariña, L., Fattorini, A., Foffano, L., Font, L., Fruck, C., Fukami, S., Fukazawa, Y., García López, R. J., Garczarczyk, M., Gasparyan, S., Gaug, M., Giesbrecht Paiva, J. G., Giglietto, N., Giordano, F., Gliwny, P., Godinović, N., Grau, R., Green, D., Green, J. G., Hadasch, D., Hahn, A., Hassan, T., Heckmann, L., Herrera, J., Hrupec, D., Hütten, M., Imazawa, R., Inada, T., Iotov, R., Ishio, K., Jiménez Martínez, I., Jormanainen, J., Kerszberg, D., Kobayashi, Y., Kubo, H., Kushida, J., Lamastra, A., Lelas, D., Leone, F., Lindfors, E., Linhoff, L., Lombardi, S., Longo, F., López-Coto, R., López-Moya, M., López-Oramas, A., Loporchio, S., Lorini, A., Lyard, E., Machado de Oliveira Fraga, B., Majumdar, P., Makariev, M., Maneva, G., Mang, N., Manganaro, M., Mangano, S., Mannheim, K., Mariotti, M., Martínez, M., Mas-Aguilar, A., Mazin, D., Menchiari, S., Mender, S., Mićanović, S., Miceli, D., Miener, T., Miranda, J. M., Mirzoyan, R., Molina, E., Mondal, H. A., Moralejo, A., Morcuende, D., Moreno, V., Nakamori, T., Nanci, C., Nava, L., Neustroev, V., Nievas Rosillo, M., Nigro, C., Nilsson, K., Nishijima, K., Njoh Ekoume, T., Noda, K., Nozaki, S., Ohtani, Y., Oka, T., Okumura, A., Otero-Santos, J., Paiano, S., Palatiello, M., Paneque, D., Paoletti, R., Paredes, J. M., Pavletić, L., Persic, M., Pihet, M., Pirola, G., Podobnik, F., Prada Moroni, P. G., Prandini, E., Principe, G., Priyadarshi, C., Rhode, W., Ribó, M., Rico, J., Righi, C., Rugliancich, A., Sahakyan, N., Saito, T., Sakurai, S., Satalecka, K., Saturni, F. G., Schleicher, B., Schmidt, K., Schmuckermaier, F., Schubert, J. L., Schweizer, T., Sitarek, J., Sliusar, V., Sobczynska, D., Spolon, A., Stamerra, A., Strišković, J., Strom, D., Strzys, M., Suda, Y., Surić, T., Tajima, H., Takahashi, M., Takeishi, R., Tavecchio, F., Temnikov, P., Terauchi, K., Terzić, T., Teshima, M., Tosti, L., Truzzi, S., Tutone, A., Ubach, S., van Scherpenberg, J., Vazquez Acosta, M., Ventura, S., Verguilov, V., Viale, I., Vigorito, C. F., Vitale, V., Vovk, I., Walter, R., Will, M., Wunderlich, C., Yamamoto, T., Zarić, D., Other, Groups, Cerruti, collaborations: M., Acosta-Pulido, J. A., Apolonio, G., Bachev, R., Baloković, M., Benítez, E., Björklund, I., Bozhilov, V., Brown, L. F., Bugg, A., Carbonell, W., Carnerero, M. I., Carosati, D., Casadio, C., Chamani, W., Chen, W. P., Chigladze, R. A., Damljanovic, G., Epps, K., Erkenov, A., Feige, M., Finke, J., Fuentes, A., Gazeas, K., Giroletti, M., Grishina, T. S., Gupta, A. C., Gurwell, M. A., Heidemann, E., Hiriart, D., Hou, W. J., Hovatta, T., Ibryamov, S., Joner, M. D., Jorstad, S. G., Kania, J., Kiehlmann, S., Kimeridze, G. N., Kopatskaya, E. N., Kopp, M., Korte, M., Kotas, B., Koyama, S., Kramer, J. A., Kunkel, L., Kurtanidze, S. O., Kurtanidze, O. M., Lähteenmäki, A., López, J. M., Larionov, V. M., Larionova, E. G., Larionova, L. V., Leto, C., Lorey, C., Mújica, R., Madejski, G. M., Marchili, N., Marscher, A. P., Minev, M., Modaressi, A., Morozova, D. A., Mufakharov, T., Myserlis, I., Nikiforova, A. A., Nikolashvili, M. G., Ovcharov, E., Perri, M., Raiteri, C. M., Readhead, A. C. S., Reimer, A., Reinhart, D., Righini, S., Rosenlehner, K., Sadun, A. C., Savchenko, S. S., Scherbantin, A., Schneider, L., Schoch, K., Seifert, D., Semkov, E., Sigua, L. A., Singh, C., Sola, P., Sotnikova, Y., Spencer, M., Steineke, R., Stojanovic, M., Strigachev, A., Tornikoski, M., Traianou, E., Tramacere, A., Troitskaya, Yu. V., Troitskiy, I. S., Trump, J. B., Tsai, A., Valcheva, A., Vasilyev, A. A., Verrecchia, F., Villata, M., Vince, O., Vrontaki, K., Weaver, Z. R., Zaharieva, E., Zottmann, N., Ministerio de Ciencia e Innovación (España), European Commission, Federal Ministry of Education and Research (Germany), Istituto Nazionale di Fisica Nucleare, Istituto Nazionale di Astrofisica, Swiss National Science Foundation, Department of Atomic Energy (India), Ministry of Education, Culture, Sports, Science and Technology (Japan), Ministry of Education and Science (Bulgaria), and Academy of Finland

Subjects
High Energy Astrophysical Phenomena (astro-ph.HE), BL Lacertae objects: individual (VER J0521+211 = RGB J0521.8+2112) – galaxies: active – galaxies: jets – gamma rays: galaxies – radiation mechanisms: non-thermal, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Astronomy and Astrophysics, Active galactic nuclei, High energy astrophysics, Blazars, BL Lacertae objects, Relativistic jets, Gamma-rays, Non-thermal radiation sources, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics - Astrophysics of Galaxies, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), ddc:520, Física nuclear, Astrophysics - High Energy Astrophysical Phenomena
Abstract

Full list of authors: Adams, C. B.; Batista, P.; Benbow, W.; Brill, A.; Brose, R.; Buckley, J. H.; Capasso, M.; Christiansen, J. L.; Errando, M.; Feng, Q.; Finley, J. P.; Foote, G. M.; Fortson, L.; Furniss, A.; Gallagher, G.; Gent, A.; Giuri, C.; Hanlon, W. F.; Hanna, D.; Hassan, T.; Hervet, O.; Holder, J.; Hona, B.; Hughes, G.; Humensky, T. B.; Jin, W.; Kaaret, P.; Kertzman, M.; Kieda, D.; Kleiner, T. K.; Krennrich, F.; Kumar, S.; Lang, M. J.; Lundy, M.; Maier, G.; Millis, J.; Moriarty, P.; Mukherjee, R.; Nievas-Rosillo, M.; Ong, R. A.; Otte, A. N.; Patel, S.; Patel, S. R.; Pfrang, K.; Pohl, M.; Prado, R. R.; Pueschel, E.; Quinn, J.; Ragan, K.; Reynolds, P. T.; Ribeiro, D.; Roache, E.; Ryan, J. L.; Sadeh, I; Santander, M.; Sembroski, G. H.; Shang, R.; Stevenson, B.; Tucci, J., V; Vassiliev, V. V.; Wakely, S. P.; Weinstein, A.; Wells, R. M.; Williams, D. A.; Williamson, T. J.; Acciari, V. A.; Aniello, T.; Ansoldi, S.; Antonelli, L. A.; Engels, A. Arbet; Arcaro, C.; Artero, M.; Asano, K.; Baack, D.; Babic, A.; Baquero, A.; de Almeida, U. Barres; Barrio, J. A.; Batkovic, I; Becerra Gonzalez, J.; Bednarek, W.; Bernardini, E.; Bernardos, M.; Berti, A.; Besenrieder, J.; Bhattacharyya, W.; Bigongiari, C.; Biland, A.; Blanch, O.; Bokenkamp, H.; Bonnoli, G.; Bosnjak, Z.; Burelli, I; Busetto, G.; Carosi, R.; Ceribella, G.; Cerruti, M.; Chai, Y.; Chilingarian, A.; Cikota, S.; Colombo, E.; Contreras, J. L.; Cortina, J.; Covino, S.; D'Amico, G.; D'Elia, V; Da Vela, P.; Dazzi, F.; De Angelis, A.; De Lotto, B.; Del Popolo, A.; Delfino, M.; Delgado, J.; Delgado Mendez, C.; Depaoli, D.; Di Pierro, F.; Di Venere, L.; Do Souto Espineira, E.; Prester, D. Dominis; Donini, A.; Dorner, D.; Doro, M.; Elsaesser, D.; Ramazani, V. Fallah; Farina, L.; Fattorini, A.; Font, L.; Fruck, C.; Fukami, S.; Fukazawa, Y.; Garcia Lopez, R. J.; Garczarczyk, M.; Gasparyan, S.; Gaug, M.; Giglietto, N.; Giordano, F.; Gliwny, P.; Godinovic, N.; Green, J. G.; Green, D.; Hadasch, D.; Hahn, A.; Hassan, T.; Heckmann, L.; Herrera, J.; Hrupec, D.; Hutten, M.; Inada, T.; Iotov, R.; Ishio, K.; Iwamura, Y.; Jimenez Martinez, I; Jormanainen, J.; Jouvin, L.; Kerszberg, D.; Kobayashi, Y.; Kubo, H.; Kushida, J.; Lamastra, A.; Lelas, D.; Leone, F.; Lindfors, E.; Linhoff, L.; Lombardi, S.; Longo, F.; Lopez-Coto, R.; Lopez-Moya, M.; Lopez-Oramas, A.; Loporchio, S.; Lorini, A.; de Oliveira Fraga, B. Machado; Maggio, C.; Majumdar, P.; Makariev, M.; Maneva, G.; Manganaro, M.; Mannheim, K.; Mariotti, M.; Martinez, M.; Aguilar, A. Mas; Mazin, D.; Menchiari, S.; Mender, S.; Micanovic, S.; Miceli, D.; Miener, T.; Miranda, J. M.; Mirzoyan, R.; Molina, E.; Mondal, H. A.; Moralejo, A.; Morcuende, D.; Moreno, V; Nakamori, T.; Nanci, C.; Nava, L.; Neustroev, V; Nievas Rosillo, M.; Nigro, C.; Nilsson, K.; Nishijima, K.; Noda, K.; Nozaki, S.; Ohtani, Y.; Oka, T.; Otero-Santos, J.; Paiano, S.; Palatiello, M.; Paneque, D.; Paoletti, R.; Paredes, J. M.; Pavletic, L.; Penil, P.; Persic, M.; Pihet, M.; Moroni, P. G. Prada; Prandini, E.; Priyadarshi, C.; Puljak, I; Rhode, W.; Ribo, M.; Rico, J.; Righi, C.; Rugliancich, A.; Sahakyan, N.; Saito, T.; Sakurai, S.; Satalecka, K.; Saturni, F. G.; Schleicher, B.; Schmidt, K.; Schmuckermaier, F.; Schubert, J. L.; Schweizer, T.; Sitarek, J.; Snidaric, I; Sobczynska, D.; Spolon, A.; Stamerra, A.; Striskovic, J.; Strom, D.; Strzys, M.; Suda, Y.; Suric, T.; Takahashi, M.; Takeishi, R.; Tavecchio, F.; Temnikov, P.; Terzic, T.; Teshima, M.; Tosti, L.; Truzzi, S.; Tutone, A.; Ubach, S.; van Scherpenberg, J.; Vanzo, G.; Vazquez Acosta, M.; Ventura, S.; Verguilov, V.; Viale, I; Vigorito, C. F.; Vitale, V.; Vovk, I; Will, M.; Wunderlich, C.; Yamamoto, T.; Zaric, D.; VERITAS Collaboration; MAGIC Collaboration.--This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited., We report on a long-lasting, elevated gamma-ray flux state from VER J0521+211 observed by VERITAS, MAGIC, and Fermi-LAT in 2013 and 2014. The peak integral flux above 200 GeV measured with the nightly binned light curve is (8.8 ± 0.4) × 10−7 photons m−2 s−1, or ∼37% of the Crab Nebula flux. Multiwavelength observations from X-ray, UV, and optical instruments are also presented. A moderate correlation between the X-ray and TeV gamma-ray fluxes was observed, and the X-ray spectrum appeared harder when the flux was higher. Using the gamma-ray spectrum and four models of the extragalactic background light (EBL), a conservative 95% confidence upper limit on the redshift of the source was found to be z ≤ 0.31. Unlike the gamma-ray and X-ray bands, the optical flux did not increase significantly during the studied period compared to the archival low-state flux. The spectral variability from optical to X-ray bands suggests that the synchrotron peak of the spectral energy distribution (SED) may become broader during flaring states, which can be adequately described with a one-zone synchrotron self-Compton model varying the high-energy end of the underlying particle spectrum. The synchrotron peak frequency of the SED and the radio morphology of the jet from the MOJAVE program are consistent with the source being an intermediate-frequency-peaked BL Lac object. © 2022. The Author(s). Published by the American Astronomical Society., This research is supported by grants from the U.S. Department of Energy Office of Science, the U.S. National Science Foundation, and the Smithsonian Institution in the U.S.; by NSERC in Canada; and by the Helmholtz Association in Germany. This research used resources provided by the Open Science Grid, which is supported by the National Science Foundation and the U.S. Department of Energy's Office of Science, and resources of the National Energy Research Scientific Computing Center (NERSC), a U.S. Department of Energy Office of Science User Facility operated under contract No. DE-AC02-05CH11231. We acknowledge the excellent work of the technical support staff at the Fred Lawrence Whipple Observatory and at the collaborating institutions in the construction and operation of the instrument. The MAGIC Collaboration would like to thank the Instituto de Astrofísica de Canarias for the excellent working conditions at the Observatorio del Roque de los Muchachos in La Palma. The financial support of the German BMBF, MPG, and HGF; the Italian INFN and INAF; the Swiss National Fund SNF; the ERDF under the Spanish Ministerio de Ciencia e Innovación (MICINN) (PID2019-104114RB-C31, PID2019-104114RB-C32, PID2019-104114RB-C33, PID2019-105510GB-C31,PID2019-107847RB-C41, PID2019-107847RB-C42, PID2019-107847RB-C44, PID2019-107988GB-C22); the Indian Department of Atomic Energy; the Japanese ICRR, the University of Tokyo, JSPS, and MEXT; the Bulgarian Ministry of Education and Science, National RI Roadmap Project DO1-400/18.12.2020; and the Academy of Finland grant No. 320045 is gratefully acknowledged. This work was also supported by the Spanish Centro de Excelencia "Severo Ochoa" (SEV-2016-0588, SEV-2017-0709, CEX2019-000920-S), the Unidad de Excelencia "María de Maeztu" (CEX2019-000918-M, MDM-2015-0509-18-2), and the CERCA program of the Generalitat de Catalunya; by the Croatian Science Foundation (HrZZ) Project IP-2016-06-9782 and the University of Rijeka Project uniri-prirod-18-48; by the DFG Collaborative Research Centers SFB823/C4 and SFB876/C3; by the Polish National Research Centre grant UMO-2016/22/M/ST9/00382; and by the Brazilian MCTIC, CNPq, and FAPERJ. Q.F. was supported by NSF grant PHY-1806554 at Barnard College.

Published
2022
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34. The WISSH quasars project. IX. Cold gas content and environment of luminous QSOs at z {ensuremath{sim}} 2.4-4.7

Author

Bischetti M., Feruglio C., Piconcelli E., Duras F., Perez-Torres M., Herrero R., Venturi G., Carniani S., Bruni G., Gavignaud I., Testa V., Bongiorno A., Brusa M., Circosta C., Cresci G., D'Odorico V., Maiolino R., Marconi A., Mingozzi M., Pappalardo C., Perna M., Traianou E., Travascio A., Vietri G., Zappacosta L., Fiore F., and Bischetti M., Feruglio C., Piconcelli E., Duras F., Perez-Torres M., Herrero R., Venturi G., Carniani S., Bruni G., Gavignaud I., Testa V., Bongiorno A., Brusa M., Circosta C., Cresci G., D'Odorico V., Maiolino R., Marconi A., Mingozzi M., Pappalardo C., Perna M., Traianou E., Travascio A., Vietri G., Zappacosta L., Fiore F.

Subjects
Astrophysics::High Energy Astrophysical Phenomena, galaxies: high-redshift, galaxies: ISM, techniques: interferometric, quasars: supermassive black holes, submillimeter: galaxies, quasars: emission lines, Astrophysics - Astrophysics of Galaxies, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics::Galaxy Astrophysics
Abstract

Context. Sources at the brightest end of the quasi-stellar object (QSO) luminosity function, during the peak epoch in the history of star formation and black hole accretion (z ∼ 2-4, often referred to as "Cosmic noon") are privileged sites to study the cycle of feeding & feedback processes in massive galaxies. Aims: We aim to perform the first systematic study of cold gas properties in the most luminous QSOs, by characterising their host-galaxies and environment. These targets exhibit indeed widespread evidence of outflows at nuclear and galactic scales. Methods: We analyse ALMA, NOEMA and JVLA observations of the far-infrared continuum, CO and [CII] emission lines in eight QSOs (bolometric luminosity LBol ≳ 3 × 1047 erg s-1) from the WISE-SDSS selected hyper-luminous (WISSH) QSOs sample at z ∼ 2.4-4.7. Results: We report a 100% emission line detection rate and a 80% detection rate in continuum emission, and we find CO emission to be consistent with the steepest CO ladders observed so far. Sub-millimetre data reveal presence of (one or more) bright companion galaxies around ∼80% of WISSH QSOs, at projected distances of ∼6-130 kpc. We observe a variety of sizes for the molecular gas reservoirs (∼1.7-10 kpc), mostly associated with rotating disks with disturbed kinematics. WISSH QSOs typically show lower CO luminosity and higher star formation efficiency than infrared matched, z ∼ 0-3 main-sequence galaxies, implying that, given the observed SFR ∼170-1100 M⊙ yr-1, molecular gas is converted into stars in ≲50 Myr. Most targets show extreme dynamical to black-hole mass ratios Mdyn/MBH ∼ 3-10, two orders of magnitude smaller than local relations. The molecular gas fraction in the host-galaxies of WISSH is lower by a factor of ∼10-100 than in star forming galaxies with similar M*. Conclusions: Our analysis reveals that hyper-luminous QSOs at Cosmic noon undergo an intense growth phase of both the central super-massive black hole and of the host-galaxy. These systems pinpoint the high-density sites where giant galaxies assemble, where we show that mergers play a major role in the build-up of the final host-galaxy mass. We suggest that the observed low molecular gas fraction and short depletion timescale are due to AGN feedback, whose presence is indicated by fast AGN-driven ionised outflows in all our targets.

Published
2021

35. New jet feature in the parsec-scale jet of the blazar OJ 287 connected to the 2017 teraelectronvolt flaring activity

Author

Lico, R., primary, Casadio, C., additional, Jorstad, S. G., additional, Gómez, J. L., additional, Marscher, A. P., additional, Traianou, E., additional, Kim, J.-Y., additional, Zhao, G.-Y., additional, Fuentes, A., additional, Cho, I., additional, Krichbaum, T. P., additional, Hervet, O., additional, O’Brien, S., additional, Boccardi, B., additional, Myserlis, I., additional, Agudo, I., additional, Alberdi, A., additional, Weaver, Z. R., additional, and Zensus, J. A., additional

Published
2022
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36. First M87 Event Horizon Telescope Results. VIII. Magnetic Field Structure near the Event Horizon

Author

Akiyama, K. Algaba, J.C. Alberdi, A. Alef, W. Anantua, R. Asada, K. Azulay, R. Baczko, A.-K. Ball, D. Baloković, M. Barrett, J. Benson, B.A. Bintley, D. Blackburn, L. Blundell, R. Boland, W. Bouman, K.L. Bower, G.C. Boyce, H. Bremer, M. Brinkerink, C.D. Brissenden, R. Britzen, S. Broderick, A.E. Broguiere, D. Bronzwaer, T. Byun, D.-Y. Carlstrom, J.E. Chael, A. Chan, C.-K. Chatterjee, S. Chatterjee, K. Chen, M.-T. Chen, Y. Chesler, P.M. Cho, I. Christian, P. Conway, J.E. Cordes, J.M. Crawford, T.M. Crew, G.B. Cruz-Osorio, A. Cui, Y. Davelaar, J. De Laurentis, M. Deane, R. Dempsey, J. Desvignes, G. Dexter, J. Doeleman, S.S. Eatough, R.P. Falcke, H. Farah, J. Fish, V.L. Fomalont, E. Ford, H.A. Fraga-Encinas, R. Friberg, P. Fromm, C.M. Fuentes, A. Galison, P. Gammie, C.F. Garciá, R. Gelles, Z. Gentaz, O. Georgiev, B. Goddi, C. Gold, R. Gómez, J.L. Gómez-Ruiz, A.I. Gu, M. Gurwell, M. Hada, K. Haggard, D. Hecht, M.H. Hesper, R. Himwich, E. Ho, L.C. Ho, P. Honma, M. Huang, C.-W.L. Huang, L. Hughes, D.H. Ikeda, S. Inoue, M. Issaoun, S. James, D.J. Jannuzi, B.T. Janssen, M. Jeter, B. Jiang, W. Jimenez-Rosales, A. Johnson, M.D. Jorstad, S. Jung, T. Karami, M. Karuppusamy, R. Kawashima, T. Keating, G.K. Kettenis, M. Kim, D.-J. Kim, J.-Y. Kim, J. Kim, J. Kino, M. Koay, J.Y. Kofuji, Y. Koch, P.M. Koyama, S. Kramer, M. Kramer, C. Krichbaum, T.P. Kuo, C.-Y. Lauer, T.R. Lee, S.-S. Levis, A. Li, Y.-R. Li, Z. Lindqvist, M. Lico, R. Lindahl, G. Liu, J. Liu, K. Liuzzo, E. Lo, W.-P. Lobanov, A.P. Loinard, L. Lonsdale, C. Lu, R.-S. Macdonald, N.R. Mao, J. Marchili, N. Markoff, S. Marrone, D.P. Marscher, A.P. Martí-Vidal, I. Matsushita, S. Matthews, L.D. Medeiros, L. Menten, K.M. Mizuno, I. Mizuno, Y. Moran, J.M. Moriyama, K. Moscibrodzka, M. Müller, C. Musoke, G. Mejiás, A.M. Michalik, D. Nadolski, A. Nagai, H. Nagar, N.M. Nakamura, M. Narayan, R. Narayanan, G. Natarajan, I. Nathanail, A. Neilsen, J. Neri, R. Ni, C. Noutsos, A. Nowak, M.A. Okino, H. Olivares, H. Ortiz-León, G.N. Oyama, T. zel, F. Palumbo, D.C.M. Park, J. Patel, N. Pen, U.-L. Pesce, D.W. Piétu, V. Plambeck, R. Popstefanija, A. Porth, O. Pötzl, F.M. Prather, B. Preciado-López, J.A. Psaltis, D. Pu, H.-Y. Ramakrishnan, V. Rao, R. Rawlings, M.G. Raymond, A.W. Rezzolla, L. Ricarte, A. Ripperda, B. Roelofs, F. Rogers, A. Ros, E. Rose, M. Roshanineshat, A. Rottmann, H. Roy, A.L. Ruszczyk, C. Rygl, K.L.J. Sánchez, S. Sánchez-Arguelles, D. Sasada, M. Savolainen, T. Schloerb, F.P. Schuster, K.-F. Shao, L. Shen, Z. Small, D. Sohn, B.W. Soohoo, J. Sun, H. Tazaki, F. Tetarenko, A.J. Tiede, P. Tilanus, R.P.J. Titus, M. Toma, K. Torne, P. Trent, T. Traianou, E. Trippe, S. Bemmel, I.V. Van Langevelde, H.J. Van Rossum, D.R. Wagner, J. Ward-Thompson, D. Wardle, J. Weintroub, J. Wex, N. Wharton, R. Wielgus, M. Wong, G.N. Wu, Q. Yoon, D. Young, A. Young, K. Younsi, Z. Yuan, F. Yuan, Y.-F. Zensus, J.A. Zhao, G.-Y. Zhao, S.-S.

Subjects
Astrophysics::High Energy Astrophysical Phenomena, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics::Galaxy Astrophysics
Abstract

Event Horizon Telescope (EHT) observations at 230 GHz have now imaged polarized emission around the supermassive black hole in M87 on event-horizon scales. This polarized synchrotron radiation probes the structure of magnetic fields and the plasma properties near the black hole. Here we compare the resolved polarization structure observed by the EHT, along with simultaneous unresolved observations with the Atacama Large Millimeter/submillimeter Array, to expectations from theoretical models. The low fractional linear polarization in the resolved image suggests that the polarization is scrambled on scales smaller than the EHT beam, which we attribute to Faraday rotation internal to the emission region. We estimate the average density n e ∼ 104-7 cm-3, magnetic field strength B ∼ 1-30 G, and electron temperature T e ∼ (1-12) 1010 K of the radiating plasma in a simple one-zone emission model. We show that the net azimuthal linear polarization pattern may result from organized, poloidal magnetic fields in the emission region. In a quantitative comparison with a large library of simulated polarimetric images from general relativistic magnetohydrodynamic (GRMHD) simulations, we identify a subset of physical models that can explain critical features of the polarimetric EHT observations while producing a relativistic jet of sufficient power. The consistent GRMHD models are all of magnetically arrested accretion disks, where near-horizon magnetic fields are dynamically important. We use the models to infer a mass accretion rate onto the black hole in M87 of (3-20) 10-4 M o˙ yr-1. © 2021. The Author(s). Published by the American Astronomical Society..

Published
2021

37. Broadband Multi-wavelength Properties of M87 during the 2017 Event Horizon Telescope Campaign

Author

Algaba, J.C. Anczarski, J. Asada, K. Baloković, M. Chandra, S. Cui, Y.-Z. Falcone, A.D. Giroletti, M. Goddi, C. Hada, K. Haggard, D. Jorstad, S. Kaur, A. Kawashima, T. Keating, G. Kim, J.-Y. Kino, M. Komossa, S. Kravchenko, E.V. Krichbaum, T.P. Lee, S.-S. Lu, R.-S. Lucchini, M. Markoff, S. Neilsen, J. Nowak, M.A. Park, J. Principe, G. Ramakrishnan, V. Reynolds, M.T. Sasada, M. Savchenko, S.S. Williamson, K.E. Akiyama, K. Alberdi, A. Alef, W. Anantua, R. Azulay, R. Baczko, A.-K. Ball, D. Barrett, J. Bintley, D. Benson, B.A. Blackburn, L. Blundell, R. Boland, W. Bouman, K.L. Bower, G.C. Boyce, H. Bremer, M. Brinkerink, C.D. Brissenden, R. Britzen, S. Broderick, A.E. Broguiere, D. Bronzwaer, T. Byun, D.-Y. Carlstrom, J.E. Chael, A. Chan, C.-K. Chatterjee, S. Chatterjee, K. Chen, M.-T. Chen, Y. Chesler, P.M. Cho, I. Christian, P. Conway, J.E. Cordes, J.M. Crawford, T.M. Crew, G.B. Cruz-Osorio, A. Davelaar, J. De Laurentis, M. Deane, R. Dempsey, J. Desvignes, G. Dexter, J. Doeleman, S.S. Eatough, R.P. Falcke, H. Farah, J. Fish, V.L. Fomalont, E. Ford, H.A. Fraga-Encinas, R. Friberg, P. Fromm, C.M. Fuentes, A. Galison, P. Gammie, C.F. García, R. Gentaz, O. Georgiev, B. Gold, R. Gómez, J.L. Gómez-Ruiz, A.I. Gu, M. Gurwell, M. Hecht, M.H. Hesper, R. Ho, L.C. Ho, P. Honma, M. Huang, C.-W.L. Huang, L. Hughes, D.H. Ikeda, S. Inoue, M. Issaoun, S. James, D.J. Jannuzi, B.T. Janssen, M. Jeter, B. Jiang, W. Jiménez-Rosales, A. Johnson, M.D. Jung, T. Karami, M. Karuppusamy, R. Kettenis, M. Kim, D.-J. Kim, J. Kim, J. Koay, J.Y. Kofuji, Y. Koch, P.M. Koyama, S. Kramer, M. Kramer, C. Kuo, C.-Y. Lauer, T.R. Levis, A. Li, Y.-R. Li, Z. Lindqvist, M. Lico, R. Lindahl, G. Liu, J. Liu, K. Liuzzo, E. Lo, W.-P. Lobanov, A.P. Loinard, L. Lonsdale, C. Macdonald, N.R. Mao, J. Marchili, N. Marrone, D.P. Marscher, A.P. Martí-Vidal, I. Matsushita, S. Matthews, L.D. Medeiros, L. Menten, K.M. Mizuno, I. Mizuno, Y. Moran, J.M. Moriyama, K. Moscibrodzka, M. Müller, C. Musoke, G. Mejías, A.M. Nagai, H. Nagar, N.M. Nakamura, M. Narayan, R. Narayanan, G. Natarajan, I. Nathanail, A. Neri, R. Ni, C. Noutsos, A. Okino, H. Olivares, H. Ortiz-León, G.N. Oyama, T. Ozel, F. Palumbo, D.C.M. Patel, N. Pen, U.-L. Pesce, D.W. Piétu, V. Plambeck, R. Popstefanija, A. Porth, O. Pötzl, F.M. Prather, B. Preciado-López, J.A. Psaltis, D. Pu, H.-Y. Rao, R. Rawlings, M.G. Raymond, A.W. Rezzolla, L. Ricarte, A. Ripperda, B. Roelofs, F. Rogers, A. Ros, E. Rose, M. Roshanineshat, A. Rottmann, H. Roy, A.L. Ruszczyk, C. Rygl, K.L.J. Sánchez, S. Sánchez-Arguelles, D. Savolainen, T. Schloerb, F.P. Schuster, K.-F. Shao, L. Shen, Z. Small, D. Sohn, B.W. Soohoo, J. Sun, H. Tazaki, F. Tetarenko, A.J. Tiede, P. Tilanus, R.P.J. Titus, M. Toma, K. Torne, P. Trent, T. Traianou, E. Trippe, S. Van Bemmel, I. Van Langevelde, H.J. Van Rossum, D.R. Wagner, J. Ward-Thompson, D. Wardle, J. Weintroub, J. Wex, N. Wharton, R. Wielgus, M. Wong, G.N. Wu, Q. Yoon, D. Young, A. Young, K. Younsi, Z. Yuan, F. Yuan, Y.-F. Zensus, J.A. Zhao, G.-Y. Zhao, S.-S. Principe, G. Giroletti, M. D'Ammando, F. Orienti, M. Abdalla, H. Adam, R. Aharonian, F. Benkhali, F.A. Angüner, E.O. Arcaro, C. Armand, C. Armstrong, T. Ashkar, H. Backes, M. Baghmanyan, V. Barbosa Martins, V. Barnacka, A. Barnard, M. Becherini, Y. Berge, D. Bernlöhr, K. Bi, B. Böttcher, M. Boisson, C. Bolmont, J. De Bony De Lavergne, M. Breuhaus, M. Brun, F. Brun, P. Bryan, M. Büchele, M. Bulik, T. Bylund, T. Caroff, S. Carosi, A. Casanova, S. Chand, T. Chen, A. Cotter, G. Curyło, M. Damascene Mbarubucyeye, J. Davids, I.D. Davies, J. Deil, C. Devin, J. Dewilt, P. Dirson, L. Djannati-Ataï, A. Dmytriiev, A. Donath, A. Doroshenko, V. Duffy, C. Dyks, J. Egberts, K. Eichhorn, F. Einecke, S. Emery, G. Ernenwein, J.-P. Feijen, K. Fegan, S. Fiasson, A. De Clairfontaine, G.F. Fontaine, G. Funk, S. Füßling, M. Gabici, S. Gallant, Y.A. Giavitto, G. Giunti, L. Glawion, D. Glicenstein, J.F. Gottschall, D. Grondin, M.-H. Hahn, J. Haupt, M. Hermann, G. Hinton, J.A. Hofmann, W. Hoischen, C. Holch, T.L. Holler, M. Hörbe, M. Horns, D. Huber, D. Jamrozy, M. Jankowsky, D. Jankowsky, F. Jardin-Blicq, A. Joshi, V. Jung-Richardt, I. Kasai, E. Kastendieck, M.A. Katarzyński, K. Katz, U. Khangulyan, D. Khélifi, B. Klepser, S. Kluźniak, W. Komin, N. Konno, R. Kosack, K. Kostunin, D. Kreter, M. Lamanna, G. Lemiere, A. Lemoine-Goumard, M. Lenain, J.-P. Levy, C. Lohse, T. Lypova, I. Mackey, J. Majumdar, J. Malyshev, D. Malyshev, D. Marandon, V. Marchegiani, P. Marcowith, A. Mares, A. Martí-Devesa, G. Marx, R. Maurin, G. Meintjes, P.J. Meyer, M. Moderski, R. Mohamed, M. Mohrmann, L. Montanari, A. Moore, C. Morris, P. Moulin, E. Muller, J. Murach, T. Nakashima, K. Nayerhoda, A. De Naurois, M. Ndiyavala, H. Niederwanger, F. Niemiec, J. Oakes, L. O'Brien, P. Odaka, H. Ohm, S. Olivera-Nieto, L. De Ona Wilhelmi, E. Ostrowski, M. Panter, M. Panny, S. Parsons, R.D. Peron, G. Peyaud, B. Piel, Q. Pita, S. Poireau, V. Noel, A.P. Prokhorov, D.A. Prokoph, H. Pühlhofer, G. Punch, M. Quirrenbach, A. Rauth, R. Reichherzer, P. Reimer, A. Reimer, O. Remy, Q. Renaud, M. Rieger, F. Rinchiuso, L. Romoli, C. Rowell, G. Rudak, B. Ruiz-Velasco, E. Sahakian, V. Sailer, S. Sanchez, D.A. Santangelo, A. Sasaki, M. Scalici, M. Schutte, H.M. Schwanke, U. Schwemmer, S. Seglar-Arroyo, M. Senniappan, M. Seyffert, A.S. Shafi, N. Shiningayamwe, K. Simoni, R. Sinha, A. Sol, H. Specovius, A. Spencer, S. Spir-Jacob, M. Stawarz, Ł. Sun, L. Steenkamp, R. Stegmann, C. Steinmassl, S. Steppa, C. Takahashi, T. Tavernier, T. Taylor, A.M. Terrier, R. Tiziani, D. Tluczykont, M. Tomankova, L. Trichard, C. Tsirou, M. Tuffs, R. Uchiyama, Y. Van Der Walt, D.J. Van Eldik, C. Van Rensburg, C. Van Soelen, B. Vasileiadis, G. Veh, J. Venter, C. Vincent, P. Vink, J. Völk, H.J. Vuillaume, T. Wadiasingh, Z. Wagner, S.J. Watson, J. Werner, F. White, R. Wierzcholska, A. Wong, Y.W. Yusafzai, A. Zacharias, M. Zanin, R. Zargaryan, D. Zdziarski, A.A. Zech, A. Zhu, S.J. Zorn, J. Zouari, S. Żywucka, N. Acciari, V.A. Ansoldi, S. Antonelli, L.A. Engels, A.A. Artero, M. Asano, K. Baack, D. Babić, A. Baquero, A. De Almeida, U.B. Barrio, J.A. Becerra González, J. Bednarek, W. Bellizzi, L. Bernardini, E. Bernardos, M. Berti, A. Besenrieder, J. Bhattacharyya, W. Bigongiari, C. Biland, A. Blanch, O. Bonnoli, G. Bošnjak, Ž. Busetto, G. Carosi, R. Ceribella, G. Cerruti, M. Chai, Y. Chilingarian, A. Cikota, S. Colak, S.M. Colombo, E. Contreras, J.L. Cortina, J. Covino, S. D'Amico, G. D'Elia, V. Da Vela, P. Dazzi, F. De Angelis, A. De Lotto, B. Delfino, M. Delgado, J. Delgado Mendez, C. Depaoli, D. Di Pierro, F. Di Venere, L. Do Souto Espineira, E. Dominis Prester, D. Donini, A. Dorner, D. Doro, M. Elsaesser, D. Fallah Ramazani, V. Fattorini, A. Ferrara, G. Fonseca, M.V. Font, L. Fruck, C. Fukami, S. García López, R.J. Garczarczyk, M. Gasparyan, S. Gaug, M. Giglietto, N. Giordano, F. Gliwny, P. Godinović, N. Green, J.G. Green, D. Hadasch, D. Hahn, A. Heckmann, L. Herrera, J. Hoang, J. Hrupec, D. Hütten, M. Inada, T. Inoue, S. Ishio, K. Iwamura, Y. Jiménez, I. Jormanainen, J. Jouvin, L. Kajiwara, Y. Karjalainen, M. Kerszberg, D. Kobayashi, Y. Kubo, H. Kushida, J. Lamastra, A. Lelas, D. Leone, F. Lindfors, E. Lombardi, S. Longo, F. López-Coto, R. López-Moya, M. López-Oramas, A. Loporchio, S. Machado De Oliveira Fraga, B. Maggio, C. Majumdar, P. Makariev, M. Mallamaci, M. Maneva, G. Manganaro, M. Mannheim, K. Maraschi, L. Mariotti, M. Martínez, M. Mazin, D. Menchiari, S. Mender, S. Mićanović, S. Miceli, D. Miener, T. Minev, M. Miranda, J.M. Mirzoyan, R. Molina, E. Moralejo, A. Morcuende, D. Moreno, V. Moretti, E. Neustroev, V. Nigro, C. Nilsson, K. Nishijima, K. Noda, K. Nozaki, S. Ohtani, Y. Oka, T. Otero-Santos, J. Paiano, S. Palatiello, M. Paneque, D. Paoletti, R. Paredes, J.M. Pavletić, L. Penil, P. Perennes, C. Persic, M. Moroni, P.G.P. Prandini, E. Priyadarshi, C. Puljak, I. Rhode, W. Ribó, M. Rico, J. Righi, C. Rugliancich, A. Saha, L. Sahakyan, N. Saito, T. Sakurai, S. Satalecka, K. Saturni, F.G. Schleicher, B. Schmidt, K. Schweizer, T. Sitarek, J. Šnidarić, I. Sobczynska, D. Spolon, A. Stamerra, A. Strom, D. Strzys, M. Suda, Y. Surić, T. Takahashi, M. Tavecchio, F. Temnikov, P. Terzić, T. Teshima, M. Tosti, L. Truzzi, S. Tutone, A. Ubach, S. Van Scherpenberg, J. Vanzo, G. Vazquez Acosta, M. Ventura, S. Verguilov, V. Vigorito, C.F. Vitale, V. Vovk, I. Will, M. Wunderlich, C. Zarić, D. Adams, C.B. Benbow, W. Brill, A. Capasso, M. Christiansen, J.L. Chromey, A.J. Daniel, M.K. Errando, M. Farrell, K.A. Feng, Q. Finley, J.P. Fortson, L. Furniss, A. Gent, A. Giuri, C. Hassan, T. Hervet, O. Holder, J. Hughes, G. Humensky, T.B. Jin, W. Kaaret, P. Kertzman, M. Kieda, D. Kumar, S. Lang, M.J. Lundy, M. Maier, G. Moriarty, P. Mukherjee, R. Nieto, D. Nievas-Rosillo, M. O'Brien, S. Ong, R.A. Otte, A.N. Patel, S. Pfrang, K. Pohl, M. Prado, R.R. Pueschel, E. Quinn, J. Ragan, K. Reynolds, P.T. Ribeiro, D. Richards, G.T. Roache, E. Rulten, C. Ryan, J.L. Santander, M. Sembroski, G.H. Shang, R. Weinstein, A. Williams, D.A. Williamson, T.J. Hirota, T. Cui, L. Niinuma, K. Ro, H. Sakai, N. Sawada-Satoh, S. Wajima, K. Wang, N. Liu, X. Yonekura, Y.

Subjects
Astrophysics::High Energy Astrophysical Phenomena, Astrophysics::Cosmology and Extragalactic Astrophysics
Abstract

In 2017, the Event Horizon Telescope (EHT) Collaboration succeeded in capturing the first direct image of the center of the M87 galaxy. The asymmetric ring morphology and size are consistent with theoretical expectations for a weakly accreting supermassive black hole of mass ∼6.5 × 109 M o˙. The EHTC also partnered with several international facilities in space and on the ground, to arrange an extensive, quasi-simultaneous multi-wavelength campaign. This Letter presents the results and analysis of this campaign, as well as the multi-wavelength data as a legacy data repository. We captured M87 in a historically low state, and the core flux dominates over HST-1 at high energies, making it possible to combine core flux constraints with the more spatially precise very long baseline interferometry data. We present the most complete simultaneous multi-wavelength spectrum of the active nucleus to date, and discuss the complexity and caveats of combining data from different spatial scales into one broadband spectrum. We apply two heuristic, isotropic leptonic single-zone models to provide insight into the basic source properties, but conclude that a structured jet is necessary to explain M87's spectrum. We can exclude that the simultaneous γ-ray emission is produced via inverse Compton emission in the same region producing the EHT mm-band emission, and further conclude that the γ-rays can only be produced in the inner jets (inward of HST-1) if there are strongly particle-dominated regions. Direct synchrotron emission from accelerated protons and secondaries cannot yet be excluded. © 2021. The Author(s). Published by the American Astronomical Society..

Published
2021

38. Constraints on black-hole charges with the 2017 EHT observations of M87∗

Author

Kocherlakota, P. Rezzolla, L. Falcke, H. Fromm, C.M. Kramer, M. Mizuno, Y. Nathanail, A. Olivares, H. Younsi, Z. Akiyama, K. Alberdi, A. Alef, W. Algaba, J.C. Anantua, R. Asada, K. Azulay, R. Baczko, A.-K. Ball, D. Baloković, M. Barrett, J. Benson, B.A. Bintley, D. Blackburn, L. Blundell, R. Boland, W. Bouman, K.L. Bower, G.C. Boyce, H. Bremer, M. Brinkerink, C.D. Brissenden, R. Britzen, S. Broderick, A.E. Broguiere, D. Bronzwaer, T. Byun, D.-Y. Carlstrom, J.E. Chael, A. Chan, C.-K. Chatterjee, S. Chatterjee, K. Chen, M.-T. Chen, Y. Chesler, P.M. Cho, I. Christian, P. Conway, J.E. Cordes, J.M. Crawford, T.M. Crew, G.B. Cruz-Osorio, A. Cui, Y. Davelaar, J. De Laurentis, M. Deane, R. Dempsey, J. Desvignes, G. Doeleman, S.S. Eatough, R.P. Farah, J. Fish, V.L. Fomalont, E. Fraga-Encinas, R. Friberg, P. Ford, H.A. Fuentes, A. Galison, P. Gammie, C.F. García, R. Gentaz, O. Georgiev, B. Goddi, C. Gold, R. Gómez, J.L. Gómez-Ruiz, A.I. Gu, M. Gurwell, M. Hada, K. Haggard, D. Hecht, M.H. Hesper, R. Ho, L.C. Ho, P. Honma, M. Huang, C.-W.L. Huang, L. Hughes, D.H. Ikeda, S. Inoue, M. Issaoun, S. James, D.J. Jannuzi, B.T. Janssen, M. Jeter, B. Jiang, W. Jimenez-Rosales, A. Johnson, M.D. Jorstad, S. Jung, T. Karami, M. Karuppusamy, R. Kawashima, T. Keating, G.K. Kettenis, M. Kim, D.-J. Kim, J.-Y. Kim, J. Kim, J. Kino, M. Koay, J.Y. Kofuji, Y. Koch, P.M. Koyama, S. Kramer, C. Krichbaum, T.P. Kuo, C.-Y. Lauer, T.R. Lee, S.-S. Levis, A. Li, Y.-R. Li, Z. Lindqvist, M. Lico, R. Lindahl, G. Liu, J. Liu, K. Liuzzo, E. Lo, W.-P. Lobanov, A.P. Loinard, L. Lonsdale, C. Lu, R.-S. Macdonald, N.R. Mao, J. Marchili, N. Markoff, S. Marrone, D.P. Marscher, A.P. Martí-Vidal, I. Matsushita, S. Matthews, L.D. Medeiros, L. Menten, K.M. Mizuno, I. Moran, J.M. Moriyama, K. Moscibrodzka, M. Müller, C. Musoke, G. Mejías, A.M. Nagai, H. Nagar, N.M. Nakamura, M. Narayan, R. Narayanan, G. Natarajan, I. Neilsen, J. Neri, R. Ni, C. Noutsos, A. Nowak, M.A. Okino, H. Ortiz-León, G.N. Oyama, T. Özel, F. Palumbo, D.C.M. Park, J. Patel, N. Pen, U.-L. Pesce, D.W. Piétu, V. Plambeck, R. Popstefanija, A. Porth, O. Pötzl, F.M. Prather, B. Preciado-López, J.A. Psaltis, D. Pu, H.-Y. Ramakrishnan, V. Rao, R. Rawlings, M.G. Raymond, A.W. Ricarte, A. Ripperda, B. Roelofs, F. Rogers, A. Ros, E. Rose, M. Roshanineshat, A. Rottmann, H. Roy, A.L. Ruszczyk, C. Rygl, K.L.J. Sánchez, S. Sánchez-Arguelles, D. Sasada, M. Savolainen, T. Schloerb, F.P. Schuster, K.-F. Shao, L. Shen, Z. Small, D. Sohn, B.W. Soohoo, J. Sun, H. Tazaki, F. Tetarenko, A.J. Tiede, P. Tilanus, R.P.J. Titus, M. Toma, K. Torne, P. Trent, T. Traianou, E. Trippe, S. Van Bemmel, I. Van Langevelde, H.J. Van Rossum, D.R. Wagner, J. Ward-Thompson, D. Wardle, J. Weintroub, J. Wex, N. Wharton, R. Wielgus, M. Wong, G.N. Wu, Q. Yoon, D. Young, A. Young, K. Yuan, F. Yuan, Y.-F. Zensus, J.A. Zhao, G.-Y. Zhao, S.-S. (EHT Collaboration)

Subjects
General Relativity and Quantum Cosmology, Astrophysics::High Energy Astrophysical Phenomena
Abstract

Our understanding of strong gravity near supermassive compact objects has recently improved thanks to the measurements made by the Event Horizon Telescope (EHT). We use here the M87∗ shadow size to infer constraints on the physical charges of a large variety of nonrotating or rotating black holes. For example, we show that the quality of the measurements is already sufficient to rule out that M87∗ is a highly charged dilaton black hole. Similarly, when considering black holes with two physical and independent charges, we are able to exclude considerable regions of the space of parameters for the doubly-charged dilaton and the Sen black holes. © 2021 authors. Published by the American Physical Society.

Published
2021

39. Event Horizon Telescope observations of the jet launching and collimation in Centaurus A

Author

Janssen, M. Falcke, H. Kadler, M. Ros, E. Wielgus, M. Akiyama, K. Baloković, M. Blackburn, L. Bouman, K.L. Chael, A. Chan, C.-K. Chatterjee, K. Davelaar, J. Edwards, P.G. Fromm, C.M. Gómez, J.L. Goddi, C. Issaoun, S. Johnson, M.D. Kim, J. Koay, J.Y. Krichbaum, T.P. Liu, J. Liuzzo, E. Markoff, S. Markowitz, A. Marrone, D.P. Mizuno, Y. Müller, C. Ni, C. Pesce, D.W. Ramakrishnan, V. Roelofs, F. Rygl, K.L.J. van Bemmel, I. Alberdi, A. Alef, W. Algaba, J.C. Anantua, R. Asada, K. Azulay, R. Baczko, A.-K. Ball, D. Barrett, J. Benson, B.A. Bintley, D. Blundell, R. Boland, W. Bower, G.C. Boyce, H. Bremer, M. Brinkerink, C.D. Brissenden, R. Britzen, S. Broderick, A.E. Broguiere, D. Bronzwaer, T. Byun, D.-Y. Carlstrom, J.E. Chatterjee, S. Chen, M.-T. Chen, Y. Chesler, P.M. Cho, I. Christian, P. Conway, J.E. Cordes, J.M. Crawford, T.M. Crew, G.B. Cruz-Osorio, A. Cui, Y. De Laurentis, M. Deane, R. Dempsey, J. Desvignes, G. Dexter, J. Doeleman, S.S. Eatough, R.P. Farah, J. Fish, V.L. Fomalont, E. Ford, H.A. Fraga-Encinas, R. Friberg, P. Fuentes, A. Galison, P. Gammie, C.F. García, R. Gelles, Z. Gentaz, O. Georgiev, B. Gold, R. Gómez-Ruiz, A.I. Gu, M. Gurwell, M. Hada, K. Haggard, D. Hecht, M.H. Hesper, R. Himwich, E. Ho, L.C. Ho, P. Honma, M. Huang, C.-W.L. Huang, L. Hughes, D.H. Ikeda, S. Inoue, M. James, D.J. Jannuzi, B.T. Jeter, B. Jiang, W. Jimenez-Rosales, A. Jorstad, S. Jung, T. Karami, M. Karuppusamy, R. Kawashima, T. Keating, G.K. Kettenis, M. Kim, D.-J. Kim, J.-Y. Kim, J. Kino, M. Kofuji, Y. Koyama, S. Kramer, M. Kramer, C. Kuo, C.-Y. Lauer, T.R. Lee, S.-S. Levis, A. Li, Y.-R. Li, Z. Lindqvist, M. Lico, R. Lindahl, G. Liu, K. Lo, W.-P. Lobanov, A.P. Loinard, L. Lonsdale, C. Lu, R.-S. MacDonald, N.R. Mao, J. Marchili, N. Marscher, A.P. Martí-Vidal, I. Matsushita, S. Matthews, L.D. Medeiros, L. Menten, K.M. Mizuno, I. Moran, J.M. Moriyama, K. Moscibrodzka, M. Musoke, G. Mejías, A.M. Nagai, H. Nagar, N.M. Nakamura, M. Narayan, R. Narayanan, G. Natarajan, I. Nathanail, A. Neilsen, J. Neri, R. Noutsos, A. Nowak, M.A. Okino, H. Olivares, H. Ortiz-León, G.N. Oyama, T. Özel, F. Palumbo, D.C.M. Park, J. Patel, N. Pen, U.-L. Piétu, V. Plambeck, R. PopStefanija, A. Porth, O. Pötzl, F.M. Prather, B. Preciado-López, J.A. Psaltis, D. Pu, H.-Y. Rao, R. Rawlings, M.G. Raymond, A.W. Rezzolla, L. Ricarte, A. Ripperda, B. Rogers, A. Rose, M. Roshanineshat, A. Rottmann, H. Roy, A.L. Ruszczyk, C. Sánchez, S. Sánchez-Arguelles, D. Sasada, M. Savolainen, T. Schloerb, F.P. Schuster, K.-F. Shao, L. Shen, Z. Small, D. Sohn, B.W. SooHoo, J. Sun, H. Tazaki, F. Tetarenko, A.J. Tiede, P. Tilanus, R.P.J. Titus, M. Torne, P. Trent, T. Traianou, E. Trippe, S. van Bemmel, I. van Langevelde, H.J. van Rossum, D.R. Wagner, J. Ward-Thompson, D. Wardle, J. Weintroub, J. Wex, N. Wharton, R. Wong, G.N. Wu, Q. Yoon, D. Young, A. Young, K. Younsi, Z. Yuan, F. Yuan, Y.-F. Zensus, J.A. Zhao, G.-Y. Zhao, S.-S. The Event Horizon Telescope Collaboration

Abstract

Very-long-baseline interferometry (VLBI) observations of active galactic nuclei at millimetre wavelengths have the power to reveal the launching and initial collimation region of extragalactic radio jets, down to 10–100 gravitational radii (rg ≡ GM/c2) scales in nearby sources1. Centaurus A is the closest radio-loud source to Earth2. It bridges the gap in mass and accretion rate between the supermassive black holes (SMBHs) in Messier 87 and our Galactic Centre. A large southern declination of −43° has, however, prevented VLBI imaging of Centaurus A below a wavelength of 1 cm thus far. Here we show the millimetre VLBI image of the source, which we obtained with the Event Horizon Telescope at 228 GHz. Compared with previous observations3, we image the jet of Centaurus A at a tenfold higher frequency and sixteen times sharper resolution and thereby probe sub-lightday structures. We reveal a highly collimated, asymmetrically edge-brightened jet as well as the fainter counterjet. We find that the source structure of Centaurus A resembles the jet in Messier 87 on ~500 rg scales remarkably well. Furthermore, we identify the location of Centaurus A’s SMBH with respect to its resolved jet core at a wavelength of 1.3 mm and conclude that the source’s event horizon shadow4 should be visible at terahertz frequencies. This location further supports the universal scale invariance of black holes over a wide range of masses5,6. © 2021, The Author(s).

Published
2021

40. Polarimetric Properties of Event Horizon Telescope Targets from ALMA

Author

Goddi, C. Martí-Vidal, I. Messias, H. Bower, G.C. Broderick, A.E. Dexter, J. Marrone, D.P. Moscibrodzka, M. Nagai, H. Algaba, J.C. Asada, K. Crew, G.B. Gómez, J.L. Impellizzeri, C.M.V. Janssen, M. Kadler, M. Krichbaum, T.P. Lico, R. Matthews, L.D. Nathanail, A. Ricarte, A. Ros, E. Younsi, Z. Akiyama, K. Alberdi, A. Alef, W. Anantua, R. Azulay, R. Baczko, A.-K. Ball, D. Baloković, M. Barrett, J. Benson, B.A. Bintley, D. Blackburn, L. Blundell, R. Boland, W. Bouman, K.L. Boyce, H. Bremer, M. Brinkerink, C.D. Brissenden, R. Britzen, S. Broguiere, D. Bronzwaer, T. Byun, D.-Y. Carlstrom, J.E. Chael, A. Chan, C.-K. Chatterjee, S. Chatterjee, K. Chen, M.-T. Chen, Y. Chesler, P.M. Cho, I. Christian, P. Conway, J.E. Cordes, J.M. Crawford, T.M. Cruz-Osorio, A. Cui, Y. Davelaar, J. De Laurentis, M. Deane, R. Dempsey, J. Desvignes, G. Doeleman, S.S. Eatough, R.P. Falcke, H. Farah, J. Fish, V.L. Fomalont, E. Ford, H.A. Fraga-Encinas, R. Freeman, W.T. Friberg, P. Fromm, C.M. Fuentes, A. Galison, P. Gammie, C.F. Garciá, R. Gentaz, O. Georgiev, B. Gold, R. Gómez-Ruiz, A.I. Gu, M. Gurwell, M. Hada, K. Haggard, D. Hecht, M.H. Hesper, R. Ho, L.C. Ho, P. Honma, M. Huang, C.-W.L. Huang, L. Hughes, D.H. Inoue, M. Issaoun, S. James, D.J. Jannuzi, B.T. Jeter, B. Jiang, W. Jimenez-Rosales, A. Johnson, M.D. Jorstad, S. Jung, T. Karami, M. Karuppusamy, R. Kawashima, T. Keating, G.K. Kettenis, M. Kim, D.-J. Kim, J.-Y. Kim, J. Kim, J. Kino, M. Koay, J.Y. Kofuji, Y. Koch, P.M. Koyama, S. Kramer, M. Kramer, C. Kuo, C.-Y. Lauer, T.R. Lee, S.-S. Levis, A. Li, Y.-R. Li, Z. Lindqvist, M. Lindahl, G. Liu, J. Liu, K. Liuzzo, E. Lo, W.-P. Lobanov, A.P. Loinard, L. Lonsdale, C. Lu, R.-S. Macdonald, N.R. Mao, J. Marchili, N. Markoff, S. Marscher, A.P. Matsushita, S. Medeiros, L. Menten, K.M. Mizuno, I. Mizuno, Y. Moran, J.M. Moriyama, K. Müller, C. Musoke, G. Mejiás, A.M. Nagar, N.M. Nakamura, M. Narayan, R. Narayanan, G. Natarajan, I. Neilsen, J. Neri, R. Ni, C. Noutsos, A. Nowak, M.A. Okino, H. Olivares, H. Ortiz-León, G.N. Oyama, T. zel, F. Palumbo, D.C.M. Park, J. Patel, N. Pen, U.-L. Pesce, D.W. Piétu, V. Plambeck, R. Popstefanija, A. Porth, O. Pötzl, F.M. Prather, B. Preciado-López, J.A. Psaltis, D. Pu, H.-Y. Ramakrishnan, V. Rao, R. Rawlings, M.G. Raymond, A.W. Rezzolla, L. Ripperda, B. Roelofs, F. Rogers, A. Rose, M. Roshanineshat, A. Rottmann, H. Roy, A.L. Ruszczyk, C. Rygl, K.L.J. Sánchez, S. Sánchez-Arguelles, D. Sasada, M. Savolainen, T. Schloerb, F.P. Schuster, K.-F. Shao, L. Shen, Z. Small, D. Sohn, B.W. Soohoo, J. Sun, H. Tazaki, F. Tetarenko, A.J. Tiede, P. Tilanus, R.P.J. Titus, M. Toma, K. Torne, P. Trent, T. Traianou, E. Trippe, S. Bemmel, I.V. Van Langevelde, H.J. Van Rossum, D.R. Wagner, J. Ward-Thompson, D. Wardle, J. Weintroub, J. Wex, N. Wharton, R. Wielgus, M. Wong, G.N. Wu, Q. Yoon, D. Young, A. Young, K. Yuan, F. Yuan, Y.-F. Zensus, J.A. Zhao, G.-Y. Zhao, S.-S. Bruni, G. Gopakumar, A. Hernández-Gómez, A. Herrero-Illana, R. Ingram, A. Komossa, S. Kovalev, Y.Y. Muders, D. Perucho, M. Rösch, F. Valtonen, M.

Abstract

We present the results from a full polarization study carried out with the Atacama Large Millimeter/submillimeter Array (ALMA) during the first Very Long Baseline Interferometry (VLBI) campaign, which was conducted in 2017 April in the λ3 mm and λ1.3 mm bands, in concert with the Global mm-VLBI Array (GMVA) and the Event Horizon Telescope (EHT), respectively. We determine the polarization and Faraday properties of all VLBI targets, including Sgr A∗, M87, and a dozen radio-loud active galactic nuclei (AGNs), in the two bands at several epochs in a time window of 10 days. We detect high linear polarization fractions (2%-15%) and large rotation measures (RM > 103.3-105.5 rad m-2), confirming the trends of previous AGN studies at millimeter wavelengths. We find that blazars are more strongly polarized than other AGNs in the sample, while exhibiting (on average) order-of-magnitude lower RM values, consistent with the AGN viewing angle unification scheme. For Sgr A∗ we report a mean RM of (-4.2 0.3) 105 rad m-2 at 1.3 mm, consistent with measurements over the past decade and, for the first time, an RM of (-2.1 0.1) 105 rad m-2 at 3 mm, suggesting that about half of the Faraday rotation at 1.3 mm may occur between the 3 mm photosphere and the 1.3 mm source. We also report the first unambiguous measurement of RM toward the M87 nucleus at millimeter wavelengths, which undergoes significant changes in magnitude and sign reversals on a one year timescale, spanning the range from -1.2 to 0.3 105 rad m-2 at 3 mm and -4.1 to 1.5 105 rad m-2 at 1.3 mm. Given this time variability, we argue that, unlike the case of Sgr A∗, the RM in M87 does not provide an accurate estimate of the mass accretion rate onto the black hole. We put forward a two-component model, comprised of a variable compact region and a static extended region, that can simultaneously explain the polarimetric properties observed by both the EHT (on horizon scales) and ALMA (which observes the combined emission from both components). These measurements provide critical constraints for the calibration, analysis, and interpretation of simultaneously obtained VLBI data with the EHT and GMVA. © 2021. The American Astronomical Society.

Published
2021

41. Broadband Multi-wavelength Properties of M87 during the 2017 Event Horizon Telescope Campaign

Author

Algaba, J. C., Anczarski, J., Asada, K., Baloković, M., Chandra, S., Cui, Y. -Z, Falcone, A. D., Giroletti, M., Goddi, C., Hada, K., Haggard, D., Jorstad, S., Kaur, A., Kawashima, T., Keating, G., Kim, J. -Y, Kino, M., Komossa, S., Kravchenko, E. V., Krichbaum, T. P., Lee, S. -S, Lu, R. -S, Lucchini, M., Markoff, S., Neilsen, J., Nowak, M. A., Park, J., Principe, G., Ramakrishnan, V., Reynolds, M. T., Sasada, M., Savchenko, S. S., Williamson, K. E., Akiyama, K., Alberdi, A., Alef, W., Anantua, R., Azulay, R., Baczko, A. -K, Ball, D., Barrett, J., Bintley, D., Benson, B. A., Blackburn, L., Blundell, R., Boland, W., Bouman, K. L., Bower, G. C., Boyce, H., Bremer, M., Brinkerink, C. D., Brissenden, R., Britzen, S., Broderick, A. E., Broguiere, D., Bronzwaer, T., Byun, D. -Y, Carlstrom, J. E., Chael, A., Chan, C. -K, Chatterjee, S., Chatterjee, K., Chen, M. -T, Chen, Y., Chesler, P. M., Cho, I., Christian, P., Conway, J. E., Cordes, J. M., Crawford, T. M., Crew, G. B., Cruz-Osorio, A., Davelaar, J., De Laurentis, M., Deane, R., Dempsey, J., Desvignes, G., Dexter, J., Doeleman, S. S., Eatough, R. P., Falcke, H., Farah, J., Fish, V. L., Fomalont, E., Ford, H. A., Fraga-Encinas, R., Friberg, P., Fromm, C. M., Fuentes, A., Galison, P., Gammie, C. F., García, R., Gentaz, O., Georgiev, B., Gold, R., Gómez, J. L., Gómez-Ruiz, A. I., Gu, M., Gurwell, M., Hecht, M. H., Hesper, R., Ho, L. C., Ho, P., Honma, M., Huang, C. -WL., Huang, L., Hughes, D. H., Ikeda, S., Inoue, M., Issaoun, S., James, D. J., Jannuzi, B. T., Janssen, M., Jeter, B., Jiang, W., Jiménez-Rosales, A., Johnson, M. D., Jung, T., Karami, M., Karuppusamy, R., Kettenis, M., Kim, D. -J, Kim, J., Koay, J. Y., Kofuji, Y., Koch, P. M., Koyama, S., Kramer, M., Kramer, C., Kuo, C. -Y, Lauer, T. R., Levis, A., Li, Y. -R, Li, Z., Lindqvist, M., Lico, R., Lindahl, G., Liu, J., Liu, K., Liuzzo, E., Lo, W. -P, Lobanov, A. P., Loinard, L., Lonsdale, C., Macdonald, N. R., Mao, J., Marchili, N., Marrone, D. P., Marscher, A. P., Martí-Vidal, I., Matsushita, S., Matthews, L. D., Medeiros, L., Menten, K. M., Mizuno, I., Mizuno, Y., Moran, J. M., Moriyama, K., Moscibrodzka, M., MÃŒller, C., Musoke, G., Mejías, A. M., Nagai, H., Nagar, N. M., Nakamura, M., Narayan, R., Narayanan, G., Natarajan, I., Nathanail, A., Neri, R., Ni, C., Noutsos, A., Okino, H., Olivares, H., Ortiz-León, G. N., Oyama, T., Ozel, F., Palumbo, D. C. M., Patel, N., Pen, U. -L, Pesce, D. W., Piétu, V., Plambeck, R., Popstefanija, A., Porth, O., Pötzl, F. M., Prather, B., Preciado-López, J. A., Psaltis, D., Pu, H. -Y, Rao, R., Rawlings, M. G., Raymond, A. W., Rezzolla, L., Ricarte, A., Ripperda, B., Roelofs, F., Rogers, A., Ros, E., Rose, M., Roshanineshat, A., Rottmann, H., Roy, A. L., Ruszczyk, C., Rygl, K. L. J., Sánchez, S., Sánchez-Arguelles, D., Savolainen, T., Schloerb, F. P., Schuster, K. -F, Shao, L., Shen, Z., Small, D., Sohn, B. W., Soohoo, J., Sun, H., Tazaki, F., Tetarenko, A. J., Tiede, P., Tilanus, R. P. J., Titus, M., Toma, K., Torne, P., Trent, T., Traianou, E., Trippe, S., Van Bemmel, I., Van Langevelde, H. J., Van Rossum, D. R., Wagner, J., Ward-Thompson, D., Wardle, J., Weintroub, J., Wex, N., Wharton, R., Wielgus, M., Wong, G. N., Wu, Q., Yoon, D., Young, A., Young, K., Younsi, Z., Yuan, F., Yuan, Y. -F, Zensus, J. A., Zhao, G. -Y, Zhao, S. -S, D’Ammando, F., Orienti, M., Abdalla, H., Adam, R., Aharonian, F., Benkhali, F. A., AngÃŒner, E. O., Arcaro, C., Armand, C., Armstrong, T., Ashkar, H., Backes, M., Baghmanyan, V., Barbosa Martins, V., Barnacka, A., Barnard, M., Becherini, Yvonne, Berge, D., Bernlöhr, K., Bi, B., Böttcher, M., Boisson, C., Bolmont, J., De Bony De Lavergne, M., Breuhaus, M., Brun, F., Brun, P., Bryan, M., BÃŒchele, M., Bulik, T., Bylund, Tomas, Caroff, S., Carosi, A., Casanova, S., Chand, T., Chen, A., Cotter, G., CuryÅ‚o, M., Damascene Mbarubucyeye, J., Davids, I. D., Davies, J., Deil, C., Devin, J., Dewilt, P., Dirson, L., Djannati-Ataï, A., Dmytriiev, A., Donath, A., Doroshenko, V., Duffy, C., Dyks, J., Egberts, K., Eichhorn, F., Einecke, S., Emery, G., Ernenwein, J. -P, Feijen, K., Fegan, S., Fiasson, A., De Clairfontaine, G. F., Fontaine, G., Funk, S., FÌßling, M., Gabici, S., Gallant, Y. A., Giavitto, G., Giunti, L., Glawion, D., Glicenstein, J. F., Gottschall, D., Grondin, M. -H, Hahn, J., Haupt, M., Hermann, G., Hinton, J. A., Hofmann, W., Hoischen, C., Holch, T. L., Holler, M., Hörbe, M., Horns, D., Huber, D., Jamrozy, M., Jankowsky, D., Jankowsky, F., Jardin-Blicq, A., Joshi, V., Jung-Richardt, I., Kasai, E., Kastendieck, M. A., KatarzyÅ„ski, K., Katz, U., Khangulyan, D., Khélifi, B., Klepser, S., Kluźniak, W., Komin, N., Konno, R., Kosack, K., Kostunin, D., Kreter, M., Lamanna, G., Lemiere, A., Lemoine-Goumard, M., Lenain, J. -P, Levy, C., Lohse, T., Lypova, I., Mackey, J., Majumdar, J., Malyshev, D., Marandon, V., Marchegiani, P., Marcowith, A., Mares, A., Martí-Devesa, G., Marx, R., Maurin, G., Meintjes, P. J., Meyer, M., Moderski, R., Mohamed, M., Mohrmann, L., Montanari, A., Moore, C., Morris, P., Moulin, E., Muller, J., Murach, T., Nakashima, K., Nayerhoda, A., De Naurois, M., Ndiyavala, H., Niederwanger, F., Niemiec, J., Oakes, L., O’Brien, P., Odaka, H., Ohm, S., Olivera-Nieto, L., De Ona Wilhelmi, E., Ostrowski, M., Panter, M., Panny, S., Parsons, R. D., Peron, G., Peyaud, B., Piel, Q., Pita, S., Poireau, V., Noel, A. P., Prokhorov, D. A., Prokoph, H., PÃŒhlhofer, G., Punch, Michael, Quirrenbach, A., Rauth, R., Reichherzer, P., Reimer, A., Reimer, O., Remy, Q., Renaud, M., Rieger, F., Rinchiuso, L., Romoli, C., Rowell, G., Rudak, B., Ruiz-Velasco, E., Sahakian, V., Sailer, S., Sanchez, D. A., Santangelo, A., Sasaki, M., Scalici, M., Schutte, H. M., Schwanke, U., Schwemmer, S., Seglar-Arroyo, M., Senniappan, M., Seyffert, A. S., Shafi, N., Shiningayamwe, K., Simoni, R., Sinha, A., Sol, H., Specovius, A., Spencer, S., Spir-Jacob, M., Stawarz, Ł., Sun, L., Steenkamp, R., Stegmann, C., Steinmassl, S., Steppa, C., Takahashi, T., Tavernier, T., Taylor, A. M., Terrier, R., Tiziani, D., Tluczykont, M., Tomankova, L., Trichard, C., Tsirou, M., Tuffs, R., Uchiyama, Y., Van Der Walt, D. J., Van Eldik, C., Van Rensburg, C., Van Soelen, B., Vasileiadis, G., Veh, J., Venter, C., Vincent, P., Vink, J., Völk, H. J., Vuillaume, T., Wadiasingh, Z., Wagner, S. J., Watson, J., Werner, F., White, R., Wierzcholska, A., Wong, Y. W., Yusafzai, A., Zacharias, M., Zanin, R., Zargaryan, D., Zdziarski, A. A., Zech, A., Zhu, S. J., Zorn, J., Zouari, S., Å»ywucka, N., Acciari, V. A., Ansoldi, S., Antonelli, L. A., Engels, A. A., Artero, M., Asano, K., Baack, D., Babić, A., Baquero, A., De Almeida, U. B., Barrio, J. A., Becerra González, J., Bednarek, W., Bellizzi, L., Bernardini, E., Bernardos, M., Berti, A., Besenrieder, J., Bhattacharyya, W., Bigongiari, C., Biland, A., Blanch, O., Bonnoli, G., BoÅ¡njak, Åœ., Busetto, G., Carosi, R., Ceribella, G., Cerruti, M., Chai, Y., Chilingarian, A., Cikota, S., Colak, S. M., Colombo, E., Contreras, J. L., Cortina, J., Covino, S., D’Amico, G., D’Elia, V., Da Vela, P., Dazzi, F., De Angelis, A., De Lotto, B., Delfino, M., Delgado, J., Delgado Mendez, C., Depaoli, D., Di Pierro, F., Di Venere, L., Do Souto Espineira, E., Dominis Prester, D., Donini, A., Dorner, D., Doro, M., Elsaesser, D., Fallah Ramazani, V., Fattorini, A., Ferrara, G., Fonseca, M. V., Font, L., Fruck, C., Fukami, S., García López, R. J., Garczarczyk, M., Gasparyan, S., Gaug, M., Giglietto, N., Giordano, F., Gliwny, P., Godinović, N., Green, J. G., Green, D., Hadasch, D., Hahn, A., Heckmann, L., Herrera, J., Hoang, J., Hrupec, D., HÃŒtten, M., Inada, T., Inoue, S., Ishio, K., Iwamura, Y., Jiménez, I., Jormanainen, J., Jouvin, L., Kajiwara, Y., Karjalainen, M., Kerszberg, D., Kobayashi, Y., Kubo, H., Kushida, J., Lamastra, A., Lelas, D., Leone, F., Lindfors, E., Lombardi, S., Longo, F., López-Coto, R., López-Moya, M., López-Oramas, A., Loporchio, S., Machado De Oliveira Fraga, B., Maggio, C., Majumdar, P., Makariev, M., Mallamaci, M., Maneva, G., Manganaro, M., Mannheim, K., Maraschi, L., Mariotti, M., Martínez, M., Mazin, D., Menchiari, S., Mender, S., Mićanović, S., Miceli, D., Miener, T., Minev, M., Miranda, J. M., Mirzoyan, R., Molina, E., Moralejo, A., Morcuende, D., Moreno, V., Moretti, E., Neustroev, V., Nigro, C., Nilsson, K., Nishijima, K., Noda, K., Nozaki, S., Ohtani, Y., Oka, T., Otero-Santos, J., Paiano, S., Palatiello, M., Paneque, D., Paoletti, R., Paredes, J. M., Pavletić, L., Penil, P., Perennes, C., Persic, M., Moroni, P. G. P., Prandini, E., Priyadarshi, C., Puljak, I., Rhode, W., Ribó, M., Rico, J., Righi, C., Rugliancich, A., Saha, L., Sahakyan, N., Saito, T., Sakurai, S., Satalecka, K., Saturni, F. G., Schleicher, B., Schmidt, K., Schweizer, T., Sitarek, J., Å nidarić, I., Sobczynska, D., Spolon, A., Stamerra, A., Strom, D., Strzys, M., Suda, Y., Surić, T., Takahashi, M., Tavecchio, F., Temnikov, P., Terzić, T., Teshima, M., Tosti, L., Truzzi, S., Tutone, A., Ubach, S., Van Scherpenberg, J., Vanzo, G., Vazquez Acosta, M., Ventura, S., Verguilov, V., Vigorito, C. F., Vitale, V., Vovk, I., Will, M., Wunderlich, C., Zarić, D., Adams, C. B., Benbow, W., Brill, A., Capasso, M., Christiansen, J. L., Chromey, A. J., Daniel, M. K., Errando, M., Farrell, K. A., Feng, Q., Finley, J. P., Fortson, L., Furniss, A., Gent, A., Giuri, C., Hassan, T., Hervet, O., Holder, J., Hughes, G., Humensky, T. B., Jin, W., Kaaret, P., Kertzman, M., Kieda, D., Kumar, S., Lang, M. J., Lundy, M., Maier, G., Moriarty, P., Mukherjee, R., Nieto, D., Nievas-Rosillo, M., O’Brien, S., Ong, R. A., Otte, A. N., Patel, S., Pfrang, K., Pohl, M., Prado, R. R., Pueschel, E., Quinn, J., Ragan, K., Reynolds, P. T., Ribeiro, D., Richards, G. T., Roache, E., Rulten, C., Ryan, J. L., Santander, M., Sembroski, G. H., Shang, R., Weinstein, A., Williams, D. A., Williamson, T. J., Hirota, T., Cui, L., Niinuma, K., Ro, H., Sakai, N., Sawada-Satoh, S., Wajima, K., Wang, N., Liu, X., Yonekura, Y., Algaba, J. C., Anczarski, J., Asada, K., Baloković, M., Chandra, S., Cui, Y. -Z, Falcone, A. D., Giroletti, M., Goddi, C., Hada, K., Haggard, D., Jorstad, S., Kaur, A., Kawashima, T., Keating, G., Kim, J. -Y, Kino, M., Komossa, S., Kravchenko, E. V., Krichbaum, T. P., Lee, S. -S, Lu, R. -S, Lucchini, M., Markoff, S., Neilsen, J., Nowak, M. A., Park, J., Principe, G., Ramakrishnan, V., Reynolds, M. T., Sasada, M., Savchenko, S. S., Williamson, K. E., Akiyama, K., Alberdi, A., Alef, W., Anantua, R., Azulay, R., Baczko, A. -K, Ball, D., Barrett, J., Bintley, D., Benson, B. A., Blackburn, L., Blundell, R., Boland, W., Bouman, K. L., Bower, G. C., Boyce, H., Bremer, M., Brinkerink, C. D., Brissenden, R., Britzen, S., Broderick, A. E., Broguiere, D., Bronzwaer, T., Byun, D. -Y, Carlstrom, J. E., Chael, A., Chan, C. -K, Chatterjee, S., Chatterjee, K., Chen, M. -T, Chen, Y., Chesler, P. M., Cho, I., Christian, P., Conway, J. E., Cordes, J. M., Crawford, T. M., Crew, G. B., Cruz-Osorio, A., Davelaar, J., De Laurentis, M., Deane, R., Dempsey, J., Desvignes, G., Dexter, J., Doeleman, S. S., Eatough, R. P., Falcke, H., Farah, J., Fish, V. L., Fomalont, E., Ford, H. A., Fraga-Encinas, R., Friberg, P., Fromm, C. M., Fuentes, A., Galison, P., Gammie, C. F., García, R., Gentaz, O., Georgiev, B., Gold, R., Gómez, J. L., Gómez-Ruiz, A. I., Gu, M., Gurwell, M., Hecht, M. H., Hesper, R., Ho, L. C., Ho, P., Honma, M., Huang, C. -WL., Huang, L., Hughes, D. H., Ikeda, S., Inoue, M., Issaoun, S., James, D. J., Jannuzi, B. T., Janssen, M., Jeter, B., Jiang, W., Jiménez-Rosales, A., Johnson, M. D., Jung, T., Karami, M., Karuppusamy, R., Kettenis, M., Kim, D. -J, Kim, J., Koay, J. Y., Kofuji, Y., Koch, P. M., Koyama, S., Kramer, M., Kramer, C., Kuo, C. -Y, Lauer, T. R., Levis, A., Li, Y. -R, Li, Z., Lindqvist, M., Lico, R., Lindahl, G., Liu, J., Liu, K., Liuzzo, E., Lo, W. -P, Lobanov, A. P., Loinard, L., Lonsdale, C., Macdonald, N. R., Mao, J., Marchili, N., Marrone, D. P., Marscher, A. P., Martí-Vidal, I., Matsushita, S., Matthews, L. D., Medeiros, L., Menten, K. M., Mizuno, I., Mizuno, Y., Moran, J. M., Moriyama, K., Moscibrodzka, M., MÃŒller, C., Musoke, G., Mejías, A. M., Nagai, H., Nagar, N. M., Nakamura, M., Narayan, R., Narayanan, G., Natarajan, I., Nathanail, A., Neri, R., Ni, C., Noutsos, A., Okino, H., Olivares, H., Ortiz-León, G. N., Oyama, T., Ozel, F., Palumbo, D. C. M., Patel, N., Pen, U. -L, Pesce, D. W., Piétu, V., Plambeck, R., Popstefanija, A., Porth, O., Pötzl, F. M., Prather, B., Preciado-López, J. A., Psaltis, D., Pu, H. -Y, Rao, R., Rawlings, M. G., Raymond, A. W., Rezzolla, L., Ricarte, A., Ripperda, B., Roelofs, F., Rogers, A., Ros, E., Rose, M., Roshanineshat, A., Rottmann, H., Roy, A. L., Ruszczyk, C., Rygl, K. L. J., Sánchez, S., Sánchez-Arguelles, D., Savolainen, T., Schloerb, F. P., Schuster, K. -F, Shao, L., Shen, Z., Small, D., Sohn, B. W., Soohoo, J., Sun, H., Tazaki, F., Tetarenko, A. J., Tiede, P., Tilanus, R. P. J., Titus, M., Toma, K., Torne, P., Trent, T., Traianou, E., Trippe, S., Van Bemmel, I., Van Langevelde, H. J., Van Rossum, D. R., Wagner, J., Ward-Thompson, D., Wardle, J., Weintroub, J., Wex, N., Wharton, R., Wielgus, M., Wong, G. N., Wu, Q., Yoon, D., Young, A., Young, K., Younsi, Z., Yuan, F., Yuan, Y. -F, Zensus, J. A., Zhao, G. -Y, Zhao, S. -S, D’Ammando, F., Orienti, M., Abdalla, H., Adam, R., Aharonian, F., Benkhali, F. A., AngÃŒner, E. O., Arcaro, C., Armand, C., Armstrong, T., Ashkar, H., Backes, M., Baghmanyan, V., Barbosa Martins, V., Barnacka, A., Barnard, M., Becherini, Yvonne, Berge, D., Bernlöhr, K., Bi, B., Böttcher, M., Boisson, C., Bolmont, J., De Bony De Lavergne, M., Breuhaus, M., Brun, F., Brun, P., Bryan, M., BÃŒchele, M., Bulik, T., Bylund, Tomas, Caroff, S., Carosi, A., Casanova, S., Chand, T., Chen, A., Cotter, G., CuryÅ‚o, M., Damascene Mbarubucyeye, J., Davids, I. D., Davies, J., Deil, C., Devin, J., Dewilt, P., Dirson, L., Djannati-Ataï, A., Dmytriiev, A., Donath, A., Doroshenko, V., Duffy, C., Dyks, J., Egberts, K., Eichhorn, F., Einecke, S., Emery, G., Ernenwein, J. -P, Feijen, K., Fegan, S., Fiasson, A., De Clairfontaine, G. F., Fontaine, G., Funk, S., FÌßling, M., Gabici, S., Gallant, Y. A., Giavitto, G., Giunti, L., Glawion, D., Glicenstein, J. F., Gottschall, D., Grondin, M. -H, Hahn, J., Haupt, M., Hermann, G., Hinton, J. A., Hofmann, W., Hoischen, C., Holch, T. L., Holler, M., Hörbe, M., Horns, D., Huber, D., Jamrozy, M., Jankowsky, D., Jankowsky, F., Jardin-Blicq, A., Joshi, V., Jung-Richardt, I., Kasai, E., Kastendieck, M. A., KatarzyÅ„ski, K., Katz, U., Khangulyan, D., Khélifi, B., Klepser, S., Kluźniak, W., Komin, N., Konno, R., Kosack, K., Kostunin, D., Kreter, M., Lamanna, G., Lemiere, A., Lemoine-Goumard, M., Lenain, J. -P, Levy, C., Lohse, T., Lypova, I., Mackey, J., Majumdar, J., Malyshev, D., Marandon, V., Marchegiani, P., Marcowith, A., Mares, A., Martí-Devesa, G., Marx, R., Maurin, G., Meintjes, P. J., Meyer, M., Moderski, R., Mohamed, M., Mohrmann, L., Montanari, A., Moore, C., Morris, P., Moulin, E., Muller, J., Murach, T., Nakashima, K., Nayerhoda, A., De Naurois, M., Ndiyavala, H., Niederwanger, F., Niemiec, J., Oakes, L., O’Brien, P., Odaka, H., Ohm, S., Olivera-Nieto, L., De Ona Wilhelmi, E., Ostrowski, M., Panter, M., Panny, S., Parsons, R. D., Peron, G., Peyaud, B., Piel, Q., Pita, S., Poireau, V., Noel, A. P., Prokhorov, D. A., Prokoph, H., PÃŒhlhofer, G., Punch, Michael, Quirrenbach, A., Rauth, R., Reichherzer, P., Reimer, A., Reimer, O., Remy, Q., Renaud, M., Rieger, F., Rinchiuso, L., Romoli, C., Rowell, G., Rudak, B., Ruiz-Velasco, E., Sahakian, V., Sailer, S., Sanchez, D. A., Santangelo, A., Sasaki, M., Scalici, M., Schutte, H. M., Schwanke, U., Schwemmer, S., Seglar-Arroyo, M., Senniappan, M., Seyffert, A. S., Shafi, N., Shiningayamwe, K., Simoni, R., Sinha, A., Sol, H., Specovius, A., Spencer, S., Spir-Jacob, M., Stawarz, Ł., Sun, L., Steenkamp, R., Stegmann, C., Steinmassl, S., Steppa, C., Takahashi, T., Tavernier, T., Taylor, A. M., Terrier, R., Tiziani, D., Tluczykont, M., Tomankova, L., Trichard, C., Tsirou, M., Tuffs, R., Uchiyama, Y., Van Der Walt, D. J., Van Eldik, C., Van Rensburg, C., Van Soelen, B., Vasileiadis, G., Veh, J., Venter, C., Vincent, P., Vink, J., Völk, H. J., Vuillaume, T., Wadiasingh, Z., Wagner, S. J., Watson, J., Werner, F., White, R., Wierzcholska, A., Wong, Y. W., Yusafzai, A., Zacharias, M., Zanin, R., Zargaryan, D., Zdziarski, A. A., Zech, A., Zhu, S. J., Zorn, J., Zouari, S., Å»ywucka, N., Acciari, V. A., Ansoldi, S., Antonelli, L. A., Engels, A. A., Artero, M., Asano, K., Baack, D., Babić, A., Baquero, A., De Almeida, U. B., Barrio, J. A., Becerra González, J., Bednarek, W., Bellizzi, L., Bernardini, E., Bernardos, M., Berti, A., Besenrieder, J., Bhattacharyya, W., Bigongiari, C., Biland, A., Blanch, O., Bonnoli, G., BoÅ¡njak, Åœ., Busetto, G., Carosi, R., Ceribella, G., Cerruti, M., Chai, Y., Chilingarian, A., Cikota, S., Colak, S. M., Colombo, E., Contreras, J. L., Cortina, J., Covino, S., D’Amico, G., D’Elia, V., Da Vela, P., Dazzi, F., De Angelis, A., De Lotto, B., Delfino, M., Delgado, J., Delgado Mendez, C., Depaoli, D., Di Pierro, F., Di Venere, L., Do Souto Espineira, E., Dominis Prester, D., Donini, A., Dorner, D., Doro, M., Elsaesser, D., Fallah Ramazani, V., Fattorini, A., Ferrara, G., Fonseca, M. V., Font, L., Fruck, C., Fukami, S., García López, R. J., Garczarczyk, M., Gasparyan, S., Gaug, M., Giglietto, N., Giordano, F., Gliwny, P., Godinović, N., Green, J. G., Green, D., Hadasch, D., Hahn, A., Heckmann, L., Herrera, J., Hoang, J., Hrupec, D., HÃŒtten, M., Inada, T., Inoue, S., Ishio, K., Iwamura, Y., Jiménez, I., Jormanainen, J., Jouvin, L., Kajiwara, Y., Karjalainen, M., Kerszberg, D., Kobayashi, Y., Kubo, H., Kushida, J., Lamastra, A., Lelas, D., Leone, F., Lindfors, E., Lombardi, S., Longo, F., López-Coto, R., López-Moya, M., López-Oramas, A., Loporchio, S., Machado De Oliveira Fraga, B., Maggio, C., Majumdar, P., Makariev, M., Mallamaci, M., Maneva, G., Manganaro, M., Mannheim, K., Maraschi, L., Mariotti, M., Martínez, M., Mazin, D., Menchiari, S., Mender, S., Mićanović, S., Miceli, D., Miener, T., Minev, M., Miranda, J. M., Mirzoyan, R., Molina, E., Moralejo, A., Morcuende, D., Moreno, V., Moretti, E., Neustroev, V., Nigro, C., Nilsson, K., Nishijima, K., Noda, K., Nozaki, S., Ohtani, Y., Oka, T., Otero-Santos, J., Paiano, S., Palatiello, M., Paneque, D., Paoletti, R., Paredes, J. M., Pavletić, L., Penil, P., Perennes, C., Persic, M., Moroni, P. G. P., Prandini, E., Priyadarshi, C., Puljak, I., Rhode, W., Ribó, M., Rico, J., Righi, C., Rugliancich, A., Saha, L., Sahakyan, N., Saito, T., Sakurai, S., Satalecka, K., Saturni, F. G., Schleicher, B., Schmidt, K., Schweizer, T., Sitarek, J., Å nidarić, I., Sobczynska, D., Spolon, A., Stamerra, A., Strom, D., Strzys, M., Suda, Y., Surić, T., Takahashi, M., Tavecchio, F., Temnikov, P., Terzić, T., Teshima, M., Tosti, L., Truzzi, S., Tutone, A., Ubach, S., Van Scherpenberg, J., Vanzo, G., Vazquez Acosta, M., Ventura, S., Verguilov, V., Vigorito, C. F., Vitale, V., Vovk, I., Will, M., Wunderlich, C., Zarić, D., Adams, C. B., Benbow, W., Brill, A., Capasso, M., Christiansen, J. L., Chromey, A. J., Daniel, M. K., Errando, M., Farrell, K. A., Feng, Q., Finley, J. P., Fortson, L., Furniss, A., Gent, A., Giuri, C., Hassan, T., Hervet, O., Holder, J., Hughes, G., Humensky, T. B., Jin, W., Kaaret, P., Kertzman, M., Kieda, D., Kumar, S., Lang, M. J., Lundy, M., Maier, G., Moriarty, P., Mukherjee, R., Nieto, D., Nievas-Rosillo, M., O’Brien, S., Ong, R. A., Otte, A. N., Patel, S., Pfrang, K., Pohl, M., Prado, R. R., Pueschel, E., Quinn, J., Ragan, K., Reynolds, P. T., Ribeiro, D., Richards, G. T., Roache, E., Rulten, C., Ryan, J. L., Santander, M., Sembroski, G. H., Shang, R., Weinstein, A., Williams, D. A., Williamson, T. J., Hirota, T., Cui, L., Niinuma, K., Ro, H., Sakai, N., Sawada-Satoh, S., Wajima, K., Wang, N., Liu, X., and Yonekura, Y.

Abstract

In 2017, the Event Horizon Telescope (EHT) Collaboration succeeded in capturing the first direct image of the center of the M87 galaxy. The asymmetric ring morphology and size are consistent with theoretical expectations for a weakly accreting supermassive black hole of mass ∌6.5 × 109 M oË™. The EHTC also partnered with several international facilities in space and on the ground, to arrange an extensive, quasi-simultaneous multi-wavelength campaign. This Letter presents the results and analysis of this campaign, as well as the multi-wavelength data as a legacy data repository. We captured M87 in a historically low state, and the core flux dominates over HST-1 at high energies, making it possible to combine core flux constraints with the more spatially precise very long baseline interferometry data. We present the most complete simultaneous multi-wavelength spectrum of the active nucleus to date, and discuss the complexity and caveats of combining data from different spatial scales into one broadband spectrum. We apply two heuristic, isotropic leptonic single-zone models to provide insight into the basic source properties, but conclude that a structured jet is necessary to explain M87’s spectrum. We can exclude that the simultaneous γ-ray emission is produced via inverse Compton emission in the same region producing the EHT mm-band emission, and further conclude that the γ-rays can only be produced in the inner jets (inward of HST-1) if there are strongly particle-dominated regions. Direct synchrotron emission from accelerated protons and secondaries cannot yet be excluded. © 2021. The Author(s). Published by the American Astronomical Society..

Published
2021
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42. H.E.S.S. and MAGIC observations of a sudden cessation of a very-high-energy γ-ray flare in PKS 1510−089 in May 2016

Author

Abdalla, H. (H.), Adam, R. (R.), Aharonian, F. (F.), Benkhali, F. A. (F. Ait), Anguner, E. O. (E. O.), Arcaro, C. (C.), Armand, C. (C.), Armstrong, T. (T.), Ashkar, H. (H.), Backes, M. (M.), Baghmanyan, V. (V), Martins, V. B. (V. Barbosa), Barnacka, A. (A.), Barnard, M. (M.), Becherini, Y. (Y.), Berge, D. (D.), Bernlohr, K. (K.), Bi, B. (B.), Bottcher, M. (M.), Boisson, C. (C.), Bolmont, J. (J.), Bonnefoy, S. (S.), de Lavergne, M. d. (M. de Bony), Bregeon, J. (J.), Breuhaus, M. (M.), Brun, F. (F.), Brun, P. (P.), Bryan, M. (M.), Buchele, M. (M.), Bulik, T. (T.), Bylund, T. (T.), Caroff, S. (S.), Carosi, A. (A.), Casanova, S. (S.), Chand, T. (T.), Chandra, S. (S.), Chen, A. (A.), Cotter, G. (G.), Mbarubucyeye, J. D. (J. Damascene), Davids, I. D. (I. D.), Davies, J. (J.), Deil, C. (C.), Devin, J. (J.), DeWilt, P. (P.), Dirson, L. (L.), Djannati-Atai, A. (A.), Dmytriiev, A. (A.), Donath, A. (A.), Doroshenko, V. (V), Dyks, J. (J.), Egberts, K. (K.), Eichhorn, F. (F.), Einecke, S. (S.), Emery, G. (G.), Ernenwein, J.-P. (J-P), Feijen, K. (K.), Fegan, S. (S.), Fiasson, A. (A.), de Clairfontaine, G. F. (G. Fichet), Filipovic, M. (M.), Fontaine, G. (G.), Funk, S. (S.), Fuling, M. (M.), Gabici, S. (S.), Gallant, Y. A. (Y. A.), Giavitto, G. (G.), Giunti, L. (L.), Glawion, D. (D.), Glicenstein, J. F. (J. F.), Gottschall, D. (D.), Grondin, M.-H. (M-H), Hahn, J. (J.), Haupt, M. (M.), Hermann, G. (G.), Hinton, J. A. (J. A.), Hofmann, W. (W.), Hoischen, C. (C.), Holch, T. L. (T. L.), Holler, M. (M.), Horbe, M. (M.), Horns, D. (D.), Huber, D. (D.), Jamrozy, M. (M.), Jankowsky, D. (D.), Jankowsky, F. (F.), Jardin-Blicq, A. (A.), Joshi, V. (V), Jung-Richardt, I. (I), Kastendieck, M. A. (M. A.), Katarzynski, K. (K.), Katz, U. (U.), Khangulyan, D. (D.), Khelifi, B. (B.), Klepser, S. (S.), Kluzniak, W. (W.), Komin, N. (Nu), Konno, R. (R.), Kosack, K. (K.), Kostunin, D. (D.), Kreter, M. (M.), Lamanna, G. (G.), Lemiere, A. (A.), Lemoine-Goumard, M. (M.), Lenain, J.-P. (J-P), Levy, C. (C.), Lohse, T. (T.), Lypova, I. (I), Mackey, J. (J.), Majumdar, J. (J.), Malyshev, D. (D.), Marandon, V. (V), Marchegiani, P. (P.), Marcowith, A. (A.), Mares, A. (A.), Marti-Devesa, G. (G.), Marx, R. (R.), Maurin, G. (G.), Meintjes, P. J. (P. J.), Meyer, M. (M.), Mitchell, A. M. (A. M. W.), Moderski, R. (R.), Mohamed, M. (M.), Mohrmann, L. (L.), Montanari, A. (A.), Moore, C. (C.), Morris, P. (P.), Moulin, E. (E.), Muller, J. (J.), Murach, T. (T.), Nakashima, K. (K.), Nayerhoda, A. (A.), de Naurois, M. (M.), Ndiyavala, H. (H.), Niederwanger, F. (F.), Niemiec, D. (D.), Oakes, L. (L.), O'Brien, P. (P.), Odaka, H. (H.), Ohm, S. (S.), Olivera-Nieto, L. (L.), Wilhelmi, E. d. (E. de Ona), Ostrowski, M. (M.), Panter, M. (M.), Panny, S. (S.), Parsons, R. D. (R. D.), Peron, G. (G.), Peyaud, B. (B.), Piel, Q. (Q.), Pita, S. (S.), Poireau, V. (V), Noel, A. P. (A. Priyana), Prokhorov, D. A. (D. A.), Prokoph, H. (H.), Puhlhofer, G. (G.), Punch, M. (M.), Quirrenbach, A. (A.), Raab, S. (S.), Rauth, R. (R.), Reichherzer, P. (P.), Reimer, A. (A.), Reimer, O. (O.), Remy, Q. (Q.), Renaud, M. (M.), Rieger, F. (F.), Rinchiuso, L. (L.), Romoli, C. (C.), Rowell, G. (G.), Rudak, B. (B.), Ruiz-Velasco, E. (E.), Sahakian, V. (V), Sailer, S. (S.), Sanchez, D. A. (D. A.), Santangelo, A. (A.), Sasaki, M. (M.), Scalici, M. (M.), Schussler, F. (F.), Schutte, H. M. (H. M.), Schwanke, U. (U.), Schwemmer, S. (S.), Seglar-Arroyo, M. (M.), Senniappan, M. (M.), Seyffert, A. S. (A. S.), Shafi, N. (N.), Shiningayamwe, K. (K.), Simoni, R. (R.), Sinha, A. (A.), Sol, H. (H.), Specovius, A. (A.), Spencer, S. (S.), Sun, L. (L.), Steenkamp, R. (R.), Stegmann, C. (C.), Steinmassl, S. (S.), Steppa, C. (C.), Takahashi, T. (T.), Tavernier, T. (T.), Taylor, A. M. (A. M.), Terrier, R. (R.), Tiziani, D. (D.), Tluczykont, M. (M.), Tomankova, L. (L.), Trichard, C. (C.), Tsirou, M. (M.), Tuffs, R. (R.), Uchiyama, Y. (Y.), van der Walt, D. J. (D. J.), van Eldik, C. (C.), van Rensburg, C. (C.), van Soelen, B. (B.), Vasileiadis, G. (G.), Veh, J. (J.), Venter, C. (C.), Vincent, P. (P.), Vink, J. (J.), Volk, H. J. (H. J.), Vuillaume, T. (T.), Wadiasingh, Z. (Z.), Wagner, S. J. (S. J.), Watson, J. (J.), Werner, F. (F.), White, R. (R.), Wierzcholska, A. (A.), Wong, Y. W. (Yu W.), Yusafzai, A. (A.), Zacharias, M. (M.), Zanin, R. (R.), Zargaryan, D. (D.), Zdziarski, A. A. (A. A.), Zech, A. (A.), Zhu, S. J. (S. J.), Zorn, J. (J.), Zouari, S. (S.), Acciari, V. A. (V. A.), Ansoldi, S. (S.), Antonelli, L. A. (L. A.), Engels, A. A. (A. Arbet), Asano, K. (K.), Baack, D. (D.), Babic, A. (A.), Baquero, A. (A.), de Almeida, U. B. (U. Barres), Barrio, J. A. (J. A.), Gonzalez, J. B. (J. Becerra), Bednarek, W. (W.), Bellizzi, L. (L.), Bernardini, E. (E.), Berti, A. (A.), Besenrieder, J. (J.), Bhattacharyya, W. (W.), Bigongiari, C. (C.), Biland, A. (A.), Blanch, O. (O.), Bonnoli, G. (G.), Busetto, G. (G.), Carosi, R. (R.), Ceribella, G. (G.), Cerruti, M. (M.), Chai, Y. (Y.), Chilingarian, A. (A.), Cikota, S. (S.), Colak, S. M. (S. M.), Colin, U. (U.), Colombo, E. (E.), Contreras, J. L. (J. L.), Cortina, J. (J.), Covino, S. (S.), D'Amico, G. (G.), D'Elia, V. (V), Da Vela, P. (P.), Dazzi, F. (F.), De Angelis, A. (A.), De Lotto, B. (B.), Delfino, M. (M.), Delgado, J. (J.), Depaoli, D. (D.), Di Pierro, F. (F.), Di Venere, L. (L.), Espineira, E. D. (E. Do Souto), Prester, D. D. (D. Dominis), Donini, A. (A.), Dorner, D. (D.), Doro, M. (M.), Elsaesser, D. (D.), Ramazani, V. F. (V. Fallah), Fattorini, A. (A.), Ferrara, G. (G.), Foffano, L. (L.), Fonseca, M. V. (M., V), Font, L. (L.), Fruck, C. (C.), Fukami, S. (S.), Lopez, R. J. (R. J. Garcia), Garczarczyk, M. (M.), Gasparyan, S. (S.), Gaug, M. (M.), Giglietto, N. (N.), Giordano, F. (F.), Gliwny, P. (P.), Godinovic, N. (N.), Green, D. (D.), Hadasch, D. (D.), Hahn, A. (A.), Heckmann, L. (L.), Herrera, J. (J.), Hoang, J. (J.), Hrupec, D. (D.), Hutten, M. (M.), Inada, T. (T.), Inoue, S. (S.), Ishio, K. 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G.), Marscher, A. P. (A. P.), Boccardi, B. (B.), Casadio, C. (C.), Hodgson, J. (J.), Kim, J.-Y. (J-Y), Krichbaum, T. P. (T. P.), Lahteenmaki, A. (A.), Tornikoski, M. (M.), Traianou, E. (E.), Weaver, Z. R. (Z. R.), Abdalla, H. (H.), Adam, R. (R.), Aharonian, F. (F.), Benkhali, F. A. (F. Ait), Anguner, E. O. (E. O.), Arcaro, C. (C.), Armand, C. (C.), Armstrong, T. (T.), Ashkar, H. (H.), Backes, M. (M.), Baghmanyan, V. (V), Martins, V. B. (V. Barbosa), Barnacka, A. (A.), Barnard, M. (M.), Becherini, Y. (Y.), Berge, D. (D.), Bernlohr, K. (K.), Bi, B. (B.), Bottcher, M. (M.), Boisson, C. (C.), Bolmont, J. (J.), Bonnefoy, S. (S.), de Lavergne, M. d. (M. de Bony), Bregeon, J. (J.), Breuhaus, M. (M.), Brun, F. (F.), Brun, P. (P.), Bryan, M. (M.), Buchele, M. (M.), Bulik, T. (T.), Bylund, T. (T.), Caroff, S. (S.), Carosi, A. (A.), Casanova, S. (S.), Chand, T. (T.), Chandra, S. (S.), Chen, A. (A.), Cotter, G. (G.), Mbarubucyeye, J. D. (J. Damascene), Davids, I. D. (I. D.), Davies, J. (J.), Deil, C. (C.), Devin, J. (J.), DeWilt, P. (P.), Dirson, L. (L.), Djannati-Atai, A. (A.), Dmytriiev, A. (A.), Donath, A. (A.), Doroshenko, V. (V), Dyks, J. (J.), Egberts, K. (K.), Eichhorn, F. (F.), Einecke, S. (S.), Emery, G. (G.), Ernenwein, J.-P. (J-P), Feijen, K. (K.), Fegan, S. (S.), Fiasson, A. (A.), de Clairfontaine, G. F. (G. Fichet), Filipovic, M. (M.), Fontaine, G. (G.), Funk, S. (S.), Fuling, M. (M.), Gabici, S. (S.), Gallant, Y. A. (Y. A.), Giavitto, G. (G.), Giunti, L. (L.), Glawion, D. (D.), Glicenstein, J. F. (J. F.), Gottschall, D. (D.), Grondin, M.-H. (M-H), Hahn, J. (J.), Haupt, M. (M.), Hermann, G. (G.), Hinton, J. A. (J. A.), Hofmann, W. (W.), Hoischen, C. (C.), Holch, T. L. (T. L.), Holler, M. (M.), Horbe, M. (M.), Horns, D. (D.), Huber, D. (D.), Jamrozy, M. (M.), Jankowsky, D. (D.), Jankowsky, F. (F.), Jardin-Blicq, A. (A.), Joshi, V. (V), Jung-Richardt, I. (I), Kastendieck, M. A. (M. A.), Katarzynski, K. (K.), Katz, U. (U.), Khangulyan, D. (D.), Khelifi, B. (B.), Klepser, S. (S.), Kluzniak, W. (W.), Komin, N. (Nu), Konno, R. (R.), Kosack, K. (K.), Kostunin, D. (D.), Kreter, M. (M.), Lamanna, G. (G.), Lemiere, A. (A.), Lemoine-Goumard, M. (M.), Lenain, J.-P. (J-P), Levy, C. (C.), Lohse, T. (T.), Lypova, I. (I), Mackey, J. (J.), Majumdar, J. (J.), Malyshev, D. (D.), Marandon, V. (V), Marchegiani, P. (P.), Marcowith, A. (A.), Mares, A. (A.), Marti-Devesa, G. (G.), Marx, R. (R.), Maurin, G. (G.), Meintjes, P. J. (P. J.), Meyer, M. (M.), Mitchell, A. M. (A. M. W.), Moderski, R. (R.), Mohamed, M. (M.), Mohrmann, L. (L.), Montanari, A. (A.), Moore, C. (C.), Morris, P. (P.), Moulin, E. (E.), Muller, J. (J.), Murach, T. (T.), Nakashima, K. (K.), Nayerhoda, A. (A.), de Naurois, M. (M.), Ndiyavala, H. (H.), Niederwanger, F. (F.), Niemiec, D. (D.), Oakes, L. (L.), O'Brien, P. (P.), Odaka, H. (H.), Ohm, S. (S.), Olivera-Nieto, L. (L.), Wilhelmi, E. d. (E. de Ona), Ostrowski, M. (M.), Panter, M. (M.), Panny, S. (S.), Parsons, R. D. (R. D.), Peron, G. 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(E.), Munar-Adrover, P. (P.), Neustroev, V. (V), Nigro, C. (C.), Nilsson, K. (K.), Ninci, D. (D.), Nishijima, K. (K.), Noda, K. (K.), Nozaki, S. (S.), Ohtani, Y. (Y.), Oka, T. (T.), Otero-Santos, J. (J.), Palatiello, M. (M.), Paneque, D. (D.), Paoletti, R. (R.), Paredes, J. M. (J. M.), Pavletic, L. (L.), Penil, P. (P.), Perennes, C. (C.), Persic, M. (M.), Moroni, P. G. (P. G. Prada), Prandini, E. (E.), Priyadarshi, C. (C.), Puljak, I. (I), Rhode, W. (W.), Ribo, M. (M.), Rico, J. (J.), Righi, C. (C.), Rugliancich, A. (A.), Saha, L. (L.), Sahakyan, N. (N.), Saito, T. (T.), Sakurai, S. (S.), Satalecka, K. (K.), Schleicher, B. (B.), Schmidt, K. (K.), Schweizer, T. (T.), Sitarek, J. (J.), Snidaric, I. (I), Sobczynska, D. (D.), Spolon, A. (A.), Stamerra, A. (A.), Strom, D. (D.), Strzys, M. (M.), Suda, Y. (Y.), Suric, T. (T.), Takahashi, M. (M.), Tavecchio, F. (F.), Temnikov, P. (P.), Terzic, T. (T.), Teshima, M. (M.), Torres-Alba, N. (N.), Tosti, L. (L.), Truzzi, S. (S.), van Scherpenberg, J. (J.), Vanzo, G. (G.), Acosta, M. V. (M. Vazquez), Ventura, S. (S.), Verguilov, V. (V.), Vigorito, C. F. (C. F.), Vitale, V. (V.), Vovk, I. (I), Will, M. (M.), Zaric, D. (D.), Jorstad, S. G. (S. G.), Marscher, A. P. (A. P.), Boccardi, B. (B.), Casadio, C. (C.), Hodgson, J. (J.), Kim, J.-Y. (J-Y), Krichbaum, T. P. (T. P.), Lahteenmaki, A. (A.), Tornikoski, M. (M.), Traianou, E. (E.), and Weaver, Z. R. (Z. R.)

Abstract

The flat spectrum radio quasar (FSRQ) PKS 1510−089 is known for its complex multiwavelength behaviour and it is one of only a few FSRQs detected in very-high-energy (VHE, E > 100 GeV) γ rays. The VHE γ-ray observations with H.E.S.S. and MAGIC in late May and early June 2016 resulted in the detection of an unprecedented flare, which revealed, for the first time, VHE γ-ray intranight variability for this source. While a common variability timescale of 1.5 h has been found, there is a significant deviation near the end of the flare, with a timescale of ∼20 min marking the cessation of the event. The peak flux is nearly two orders of magnitude above the low-level emission. For the first time, a curvature was detected in the VHE γ-ray spectrum of PKS 1510–089, which can be fully explained by the absorption on the part of the extragalactic background light. Optical R-band observations with ATOM revealed a counterpart of the γ-ray flare, even though the detailed flux evolution differs from the VHE γ-ray light curve. Interestingly, a steep flux decrease was observed at the same time as the cessation of the VHE γ-ray flare. In the high-energy (HE, E > 100 MeV) γ-ray band, only a moderate flux increase was observed with Fermi-LAT, while the HE γ-ray spectrum significantly hardens up to a photon index of 1.6. A search for broad-line region (BLR) absorption features in the γ-ray spectrum indicates that the emission region is located outside of the BLR. Radio very-long-baseline interferometry observations reveal a fast-moving knot interacting with a standing jet feature around the time of the flare. As the standing feature is located ∼50 pc from the black hole, the emission region of the flare may have been located at a significant distance from the black hole. If this is indeed a true correlation, the VHE γ rays must have been produced far down in the jet, where turbulent plasma crosses a standing shock.

Published
2021

43. The complex variability of blazars: time-scales and periodicity analysis in S4 0954+65

Author

Raiteri, C M, primary, Villata, M, additional, Larionov, V M, additional, Jorstad, S G, additional, Marscher, A P, additional, Weaver, Z R, additional, Acosta-Pulido, J A, additional, Agudo, I, additional, Andreeva, T, additional, Arkharov, A, additional, Bachev, R, additional, Benítez, E, additional, Berton, M, additional, Björklund, I, additional, Borman, G A, additional, Bozhilov, V, additional, Carnerero, M I, additional, Carosati, D, additional, Casadio, C, additional, Chen, W P, additional, Damljanovic, G, additional, D’Ammando, F, additional, Escudero, J, additional, Fuentes, A, additional, Giroletti, M, additional, Grishina, T S, additional, Gupta, A C, additional, Hagen-Thorn, V A, additional, Hart, M, additional, Hiriart, D, additional, Hou, W-J, additional, Ivanov, D, additional, Kim, J-Y, additional, Kimeridze, G N, additional, Konstantopoulou, C, additional, Kopatskaya, E N, additional, Kurtanidze, O M, additional, Kurtanidze, S O, additional, Lähteenmäki, A, additional, Larionova, E G, additional, Larionova, L V, additional, Marchili, N, additional, Markovic, G, additional, Minev, M, additional, Morozova, D A, additional, Myserlis, I, additional, Nakamura, M, additional, Nikiforova, A A, additional, Nikolashvili, M G, additional, Otero-Santos, J, additional, Ovcharov, E, additional, Pursimo, T, additional, Rahimov, I, additional, Righini, S, additional, Sakamoto, T, additional, Savchenko, S S, additional, Semkov, E H, additional, Shakhovskoy, D, additional, Sigua, L A, additional, Stojanovic, M, additional, Strigachev, A, additional, Thum, C, additional, Tornikoski, M, additional, Traianou, E, additional, Troitskaya, Y V, additional, Troitskiy, I S, additional, Tsai, A, additional, Valcheva, A, additional, Vasilyev, A A, additional, Vince, O, additional, and Zaharieva, E, additional

Published
2021
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44. The jet collimation profile at high resolution in BL Lacertae

Author

Casadio, C., primary, MacDonald, N. R., additional, Boccardi, B., additional, Jorstad, S. G., additional, Marscher, A. P., additional, Krichbaum, T. P., additional, Hodgson, J. A., additional, Kim, J.-Y., additional, Traianou, E., additional, Weaver, Z. R., additional, Gómez Garrido, M., additional, González García, J., additional, Kallunki, J., additional, Lindqvist, M., additional, Sánchez, S., additional, Yang, J., additional, and Zensus, J. A., additional

Published
2021
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45. The WISSH quasars project

Author

Bischetti, M., primary, Feruglio, C., additional, Piconcelli, E., additional, Duras, F., additional, Pérez-Torres, M., additional, Herrero, R., additional, Venturi, G., additional, Carniani, S., additional, Bruni, G., additional, Gavignaud, I., additional, Testa, V., additional, Bongiorno, A., additional, Brusa, M., additional, Circosta, C., additional, Cresci, G., additional, D’Odorico, V., additional, Maiolino, R., additional, Marconi, A., additional, Mingozzi, M., additional, Pappalardo, C., additional, Perna, M., additional, Traianou, E., additional, Travascio, A., additional, Vietri, G., additional, Zappacosta, L., additional, and Fiore, F., additional

Published
2020
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46. Two Flares with One Shock: The Interesting Case of 3C 454.3

Author

Liodakis, I., primary, Blinov, D., additional, Jorstad, S. G., additional, Arkharov, A. A., additional, Paola, A. Di, additional, Efimova, N. V., additional, Grishina, T. S., additional, Kiehlmann, S., additional, Kopatskaya, E. N., additional, Larionov, V. M., additional, Larionova, L. V., additional, Larionova, E. G., additional, Marscher, A. P., additional, Morozova, D. A., additional, Nikiforova, A. A., additional, Pavlidou, V., additional, Traianou, E., additional, Troitskaya, Yu. V., additional, Troitsky, I. S., additional, Uemura, M., additional, and Weaver, Z. R., additional

Published
2020
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47. SYMBA: An end-to-end VLBI synthetic data generation pipeline

Author

Roelofs, F., primary, Janssen, M., additional, Natarajan, I., additional, Deane, R., additional, Davelaar, J., additional, Olivares, H., additional, Porth, O., additional, Paine, S. N., additional, Bouman, K. L., additional, Tilanus, R. P. J., additional, van Bemmel, I. M., additional, Falcke, H., additional, Akiyama, K., additional, Alberdi, A., additional, Alef, W., additional, Asada, K., additional, Azulay, R., additional, Baczko, A., additional, Ball, D., additional, Baloković, M., additional, Barrett, J., additional, Bintley, D., additional, Blackburn, L., additional, Boland, W., additional, Bower, G. C., additional, Bremer, M., additional, Brinkerink, C. D., additional, Brissenden, R., additional, Britzen, S., additional, Broderick, A. E., additional, Broguiere, D., additional, Bronzwaer, T., additional, Byun, D., additional, Carlstrom, J. E., additional, Chael, A., additional, Chan, C., additional, Chatterjee, S., additional, Chatterjee, K., additional, Chen, M., additional, Chen, Y., additional, Cho, I., additional, Christian, P., additional, Conway, J. E., additional, Cordes, J. M., additional, Crew, G. B., additional, Cui, Y., additional, De Laurentis, M., additional, Dempsey, J., additional, Desvignes, G., additional, Dexter, J., additional, Doeleman, S. S., additional, Eatough, R. P., additional, Fish, V. L., additional, Fomalont, E., additional, Fraga-Encinas, R., additional, Friberg, P., additional, Fromm, C. M., additional, Gómez, J. L., additional, Galison, P., additional, Gammie, C. F., additional, García, R., additional, Gentaz, O., additional, Georgiev, B., additional, Goddi, C., additional, Gold, R., additional, Gu, M., additional, Gurwell, M., additional, Hada, K., additional, Hecht, M. H., additional, Hesper, R., additional, Ho, L. C., additional, Ho, P., additional, Honma, M., additional, Huang, C. L., additional, Huang, L., additional, Hughes, D. H., additional, Ikeda, S., additional, Inoue, M., additional, Issaoun, S., additional, James, D. J., additional, Jannuzi, B. T., additional, Jeter, B., additional, Jiang, W., additional, Johnson, M. D., additional, Jorstad, S., additional, Jung, T., additional, Karami, M., additional, Karuppusamy, R., additional, Kawashima, T., additional, Keating, G. K., additional, Kettenis, M., additional, Kim, J., additional, Kino, M., additional, Koay, J. Y., additional, Koch, P. M., additional, Koyama, S., additional, Kramer, M., additional, Kramer, C., additional, Krichbaum, T. P., additional, Kuo, C., additional, Lauer, T. R., additional, Lee, S., additional, Li, Y., additional, Li, Z., additional, Lindqvist, M., additional, Lico, R., additional, Liu, K., additional, Liuzzo, E., additional, Lo, W., additional, Lobanov, A. P., additional, Loinard, L., additional, Lonsdale, C., additional, Lu, R., additional, MacDonald, N. R., additional, Mao, J., additional, Markoff, S., additional, Marrone, D. P., additional, Marscher, A. P., additional, Martí-Vidal, I., additional, Matsushita, S., additional, Matthews, L. D., additional, Medeiros, L., additional, Menten, K. M., additional, Mizuno, Y., additional, Mizuno, I., additional, Moran, J. M., additional, Moriyama, K., additional, Moscibrodzka, M., additional, Müller, C., additional, Nagai, H., additional, Nagar, N. M., additional, Nakamura, M., additional, Narayan, R., additional, Narayanan, G., additional, Neri, R., additional, Ni, C., additional, Noutsos, A., additional, Okino, H., additional, Ortiz-León, G. N., additional, Oyama, T., additional, Özel, F., additional, Palumbo, D. C. M., additional, Patel, N., additional, Pen, U., additional, Pesce, D. W., additional, Piétu, V., additional, Plambeck, R., additional, PopStefanija, A., additional, Prather, B., additional, Preciado-López, J. A., additional, Psaltis, D., additional, Pu, H., additional, Ramakrishnan, V., additional, Rao, R., additional, Rawlings, M. G., additional, Raymond, A. W., additional, Rezzolla, L., additional, Ripperda, B., additional, Rogers, A., additional, Ros, E., additional, Rose, M., additional, Roshanineshat, A., additional, Rottmann, H., additional, Roy, A. L., additional, Ruszczyk, C., additional, Ryan, B. R., additional, Rygl, K. L. J., additional, Sánchez, S., additional, Sánchez-Arguelles, D., additional, Sasada, M., additional, Savolainen, T., additional, Schloerb, F. P., additional, Schuster, K., additional, Shao, L., additional, Shen, Z., additional, Small, D., additional, Won Sohn, B., additional, SooHoo, J., additional, Tazaki, F., additional, Tiede, P., additional, Titus, M., additional, Toma, K., additional, Torne, P., additional, Traianou, E., additional, Trent, T., additional, Trippe, S., additional, Tsuda, S., additional, van Langevelde, H. J., additional, van Rossum, D. R., additional, Wagner, J., additional, Wardle, J., additional, Weintroub, J., additional, Wex, N., additional, Wharton, R., additional, Wielgus, M., additional, Wong, G. N., additional, Wu, Q., additional, Young, A., additional, Young, K., additional, Younsi, Z., additional, Yuan, F., additional, Yuan, Y., additional, Zensus, J. A., additional, Zhao, G., additional, Zhao, S., additional, and Zhu, Z., additional

Published
2020
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48. The WISSH quasars project: IX. Cold gas content and environment of luminous QSOs at z ∼ 2.4–4.7

Author

Centre National de la Recherche Scientifique (France), Max Planck Society, Ministerio de Ciencia, Innovación y Universidades (España), European Commission, Istituto Nazionale di Astrofisica, Agenzia Spaziale Italiana, European Research Council, Science and Technology Facilities Council (UK), Comisión Nacional de Investigación Científica y Tecnológica (Chile), Comunidad de Madrid, Bischetti, Manuela, Feruglio, Chiara, Piconcelli, Enrico, Duras, F., Pérez-Torres, Miguel A., Herrero, R., Venturi, G., Carniani, Stefano, Bruni, G., Gavignaud, I., Testa, V., Bongiorno, A., Brusa, Marcella, Circosta, C., Cresci, G., D'Odorico, Valentina, Maiolino, Roberto, Marconi, A., Mingozzi, M., Pappalardo, C., Perna, M., Traianou, E., Travascio, A., Vietri, G., Zappacosta, Luca, Fiore, Fabricio, Centre National de la Recherche Scientifique (France), Max Planck Society, Ministerio de Ciencia, Innovación y Universidades (España), European Commission, Istituto Nazionale di Astrofisica, Agenzia Spaziale Italiana, European Research Council, Science and Technology Facilities Council (UK), Comisión Nacional de Investigación Científica y Tecnológica (Chile), Comunidad de Madrid, Bischetti, Manuela, Feruglio, Chiara, Piconcelli, Enrico, Duras, F., Pérez-Torres, Miguel A., Herrero, R., Venturi, G., Carniani, Stefano, Bruni, G., Gavignaud, I., Testa, V., Bongiorno, A., Brusa, Marcella, Circosta, C., Cresci, G., D'Odorico, Valentina, Maiolino, Roberto, Marconi, A., Mingozzi, M., Pappalardo, C., Perna, M., Traianou, E., Travascio, A., Vietri, G., Zappacosta, Luca, and Fiore, Fabricio

Abstract

Context. Sources at the brightest end of the quasi-stellar object (QSO) luminosity function, during the peak epoch in the history of star formation and black hole accretion (z ∼ 2-4, often referred to as "Cosmic noon") are privileged sites to study the cycle of feeding & feedback processes in massive galaxies. Aims. We aim to perform the first systematic study of cold gas properties in the most luminous QSOs, by characterising their host-galaxies and environment. These targets exhibit indeed widespread evidence of outflows at nuclear and galactic scales. Methods. We analyse ALMA, NOEMA and JVLA observations of the far-infrared continuum, CO and [CII] emission lines in eight QSOs (bolometric luminosity LBol ≳ 3 × 1047 erg s-1) from the WISE-SDSS selected hyper-luminous (WISSH) QSOs sample at z ∼ 2.4-4.7. Results. We report a 100% emission line detection rate and a 80% detection rate in continuum emission, and we find CO emission to be consistent with the steepest CO ladders observed so far. Sub-millimetre data reveal presence of (one or more) bright companion galaxies around ∼80% of WISSH QSOs, at projected distances of ∼6-130 kpc. We observe a variety of sizes for the molecular gas reservoirs (∼1.7-10 kpc), mostly associated with rotating disks with disturbed kinematics. WISSH QSOs typically show lower CO luminosity and higher star formation efficiency than infrared matched, z ∼ 0-3 main-sequence galaxies, implying that, given the observed SFR ∼170-1100 M⊙ yr-1, molecular gas is converted into stars in ≲ 50 Myr. Most targets show extreme dynamical to black-hole mass ratios Mdyn/MBH ∼ 3-10, two orders of magnitude smaller than local relations. The molecular gas fraction in the host-galaxies of WISSH is lower by a factor of ∼10-100 than in star forming galaxies with similar M∗. Conclusions. Our analysis reveals that hyper-luminous QSOs at Cosmic noon undergo an intense growth phase of both the central super-massive black hole and of the host-galaxy. These s

Published
2020

49. SYMBA: An end-to-end VLBI synthetic data generation pipeline: Simulating Event Horizon Telescope observations of M 87

Author

Academy of Finland, European Commission, Alexander von Humboldt Foundation, John Templeton Foundation, China Scholarship Council, Comisión Nacional de Investigación Científica y Tecnológica (Chile), Consejo Nacional de Ciencia y Tecnología (México), European Research Council, Generalitat Valenciana, Ministerio de Economía y Competitividad (España), Ministerio de Ciencia, Innovación y Universidades (España), Gordon and Betty Moore Foundation, Istituto Nazionale di Fisica Nucleare, Japanese Government, Japan Society for the Promotion of Science, Chinese Academy of Sciences, Max Planck Society, Ministry of Science and Technology (Taiwan), National Aeronautics and Space Administration (US), National Science Foundation (US), National Natural Science Foundation of China, Natural Sciences and Engineering Research Council of Canada, National Research Foundation of Korea, Netherlands Organization for Scientific Research, National Research Foundation (South Africa), Russian Science Foundation, Ministero dell'Istruzione, dell'Università e della Ricerca, Roelofs, Freek, Janssen, M., Natarajan, I., Deane, Roger, Davelaar, J., Olivares, H., Porth, O., Paine, S. N., Bouman, Katherine L., Tilanus, R. P. J., van Bemmel, I. M., Schuster, K., Goddi, Ciriaco, Broderick, Avery E., Koay, J.Y, Ramakrishnan, V., Lobanov, A.P., Rawlings, M. G., Asada, Keiichi, Sánchez-Arguelles, D., Wong, G. N., Kim, J., Baloković, M., Roshanineshat, A., Ball, D., Hesper, R., Chatterjee, K., Titus, Michael A., Akiyama, Kazunori, Ruszczyk, Chester A., Inoue, M., Lee, S., Sasada, Mahito, Broguiere, D., Tazaki, F., Conway, J.E, Weintroub, Jonathan, Savolainen, T., Karuppusamy, R., MacDonald, N.R., Wagner, J., Young, K., Won Sohn, B., Noutsos, A., Medeiros, L., Barrett, John, van Langevelde, H. J., Zhao, Shan-Shan, Koch, P. M., Gentaz, O., Alberdi, Antxón, Ortiz-León, G. N., Wardle, J., Li, Z., Yuan, Y., Fraga-Encinas, R., Wu, Q., Fomalont, E., Falcke, H., Hada, Kazuhiro, Brinkerink, C. D., Young, A., Mao, J., Neri, Roberto, Bower, G.C., Ho, P., Chan, C., Zhao, G., Rogers, A., Patel, Nimesh, Carlstrom, J.E, Blackburn, Lindy, Christian, P., Mizuno, I., Kawashima, T., Preciado-López, J.A, Boland, W., Rottmann, H., Bremer, M., Ikeda, S., Chen, M., Jannuzi, B.T, Bronzwaer, T., James, D.J, Müller, C., Kino, Motoki, Dexter, J., Huang, C. L., Chael, A., Ni, C., Rezzolla, L., Dempsey, J., Kramer, C., Gammie, C.F, Cho, I., Trent, T., Rygl, K. L. J., Gómez, José L., Gu, M., Cui, Y., Gurwell, M., Piétu, V., Markoff, S., Shen, Z., De Laurentis, M., van Rossum, D. R., Desvignes, Gregory, Li, Y., Georgiev, B., Keating, G.K, Liu, K., Friberg, P., Lico, Rocco, Psaltis, D., Menten, K. M., Huang, L., Kuo, C., Galison, P., Ripperda, B., Toma, K., Marrone, Daniel P., Honma, M., Moscibrodzka, M., Jung, T., Gold, R., Baczko, A., Wex, N., Johnson, M. D., Ho, L. C., Younsi, Z., Liuzzo, Elisabetta, Jeter, B., Kramer, M., Small, D., Pen, U., Lauer, T.R, Byun, D., Jorstad, S., Traianou, E., Alef, W., Kettenis, Mark, Okino, H., Krichbaum, Thomas P., Prather, B., Lu, R., Wharton, R., Brissenden, R., Loinard, Laurent, Matthews, L.D., Koyama, S., Fish, Vincent L., Chatterjee, S., Martí-Vidal, Iván, Lo, W., Moriyama, K., Zensus, J. A., Sánchez, S., Cordes, J.M., Fromm, Christian M., Lonsdale, Colin J., Azulay, Rebecca, Mizuno, Y., Rose, M., Marscher, Alan P., Ros, E., Bintley, D., Shao, L., Narayanan, Gopal, Matsushita, S., Britzen, S., Doeleman, Sheperd S., Nakamura, M., SooHoo, J., Palumbo, Daniel C. M., Morán, J.M., Issaoun, Sara, García, R., Oyama, T., Nagai, H., PopStefanija, A., Chen, Y., Wielgus, Maciek, Hecht, M.H, Nagar, Neil M., Jiang, Wu, Narayan, Ramesh, Torne, P., Pesce, Dominic W., Tsuda, S., Trippe, S., Crew, Geoffrey B., Yuan, F., Raymond, Alexander W., Tiede, Paul, Özel, F., Eatough, R. P., Hughes, D. H., Rao, R., Zhu, Z., Ryan, B. R., Plambeck, R., Lindqvist, M., Karami, M., Roy, A.L., Schloerb, F. P., Pu, H., Academy of Finland, European Commission, Alexander von Humboldt Foundation, John Templeton Foundation, China Scholarship Council, Comisión Nacional de Investigación Científica y Tecnológica (Chile), Consejo Nacional de Ciencia y Tecnología (México), European Research Council, Generalitat Valenciana, Ministerio de Economía y Competitividad (España), Ministerio de Ciencia, Innovación y Universidades (España), Gordon and Betty Moore Foundation, Istituto Nazionale di Fisica Nucleare, Japanese Government, Japan Society for the Promotion of Science, Chinese Academy of Sciences, Max Planck Society, Ministry of Science and Technology (Taiwan), National Aeronautics and Space Administration (US), National Science Foundation (US), National Natural Science Foundation of China, Natural Sciences and Engineering Research Council of Canada, National Research Foundation of Korea, Netherlands Organization for Scientific Research, National Research Foundation (South Africa), Russian Science Foundation, Ministero dell'Istruzione, dell'Università e della Ricerca, Roelofs, Freek, Janssen, M., Natarajan, I., Deane, Roger, Davelaar, J., Olivares, H., Porth, O., Paine, S. N., Bouman, Katherine L., Tilanus, R. P. J., van Bemmel, I. M., Schuster, K., Goddi, Ciriaco, Broderick, Avery E., Koay, J.Y, Ramakrishnan, V., Lobanov, A.P., Rawlings, M. G., Asada, Keiichi, Sánchez-Arguelles, D., Wong, G. N., Kim, J., Baloković, M., Roshanineshat, A., Ball, D., Hesper, R., Chatterjee, K., Titus, Michael A., Akiyama, Kazunori, Ruszczyk, Chester A., Inoue, M., Lee, S., Sasada, Mahito, Broguiere, D., Tazaki, F., Conway, J.E, Weintroub, Jonathan, Savolainen, T., Karuppusamy, R., MacDonald, N.R., Wagner, J., Young, K., Won Sohn, B., Noutsos, A., Medeiros, L., Barrett, John, van Langevelde, H. J., Zhao, Shan-Shan, Koch, P. M., Gentaz, O., Alberdi, Antxón, Ortiz-León, G. N., Wardle, J., Li, Z., Yuan, Y., Fraga-Encinas, R., Wu, Q., Fomalont, E., Falcke, H., Hada, Kazuhiro, Brinkerink, C. D., Young, A., Mao, J., Neri, Roberto, Bower, G.C., Ho, P., Chan, C., Zhao, G., Rogers, A., Patel, Nimesh, Carlstrom, J.E, Blackburn, Lindy, Christian, P., Mizuno, I., Kawashima, T., Preciado-López, J.A, Boland, W., Rottmann, H., Bremer, M., Ikeda, S., Chen, M., Jannuzi, B.T, Bronzwaer, T., James, D.J, Müller, C., Kino, Motoki, Dexter, J., Huang, C. L., Chael, A., Ni, C., Rezzolla, L., Dempsey, J., Kramer, C., Gammie, C.F, Cho, I., Trent, T., Rygl, K. L. J., Gómez, José L., Gu, M., Cui, Y., Gurwell, M., Piétu, V., Markoff, S., Shen, Z., De Laurentis, M., van Rossum, D. R., Desvignes, Gregory, Li, Y., Georgiev, B., Keating, G.K, Liu, K., Friberg, P., Lico, Rocco, Psaltis, D., Menten, K. M., Huang, L., Kuo, C., Galison, P., Ripperda, B., Toma, K., Marrone, Daniel P., Honma, M., Moscibrodzka, M., Jung, T., Gold, R., Baczko, A., Wex, N., Johnson, M. D., Ho, L. C., Younsi, Z., Liuzzo, Elisabetta, Jeter, B., Kramer, M., Small, D., Pen, U., Lauer, T.R, Byun, D., Jorstad, S., Traianou, E., Alef, W., Kettenis, Mark, Okino, H., Krichbaum, Thomas P., Prather, B., Lu, R., Wharton, R., Brissenden, R., Loinard, Laurent, Matthews, L.D., Koyama, S., Fish, Vincent L., Chatterjee, S., Martí-Vidal, Iván, Lo, W., Moriyama, K., Zensus, J. A., Sánchez, S., Cordes, J.M., Fromm, Christian M., Lonsdale, Colin J., Azulay, Rebecca, Mizuno, Y., Rose, M., Marscher, Alan P., Ros, E., Bintley, D., Shao, L., Narayanan, Gopal, Matsushita, S., Britzen, S., Doeleman, Sheperd S., Nakamura, M., SooHoo, J., Palumbo, Daniel C. M., Morán, J.M., Issaoun, Sara, García, R., Oyama, T., Nagai, H., PopStefanija, A., Chen, Y., Wielgus, Maciek, Hecht, M.H, Nagar, Neil M., Jiang, Wu, Narayan, Ramesh, Torne, P., Pesce, Dominic W., Tsuda, S., Trippe, S., Crew, Geoffrey B., Yuan, F., Raymond, Alexander W., Tiede, Paul, Özel, F., Eatough, R. P., Hughes, D. H., Rao, R., Zhu, Z., Ryan, B. R., Plambeck, R., Lindqvist, M., Karami, M., Roy, A.L., Schloerb, F. P., and Pu, H.

Abstract

Context. Realistic synthetic observations of theoretical source models are essential for our understanding of real observational data. In using synthetic data, one can verify the extent to which source parameters can be recovered and evaluate how various data corruption effects can be calibrated. These studies are the most important when proposing observations of new sources, in the characterization of the capabilities of new or upgraded instruments, and when verifying model-based theoretical predictions in a direct comparison with observational data. Aims. We present the SYnthetic Measurement creator for long Baseline Arrays (SYMBA), a novel synthetic data generation pipeline for Very Long Baseline Interferometry (VLBI) observations. SYMBA takes into account several realistic atmospheric, instrumental, and calibration effects. Methods. We used SYMBA to create synthetic observations for the Event Horizon Telescope (EHT), a millimetre VLBI array, which has recently captured the first image of a black hole shadow. After testing SYMBA with simple source and corruption models, we study the importance of including all corruption and calibration effects, compared to the addition of thermal noise only. Using synthetic data based on two example general relativistic magnetohydrodynamics (GRMHD) model images of M 87, we performed case studies to assess the image quality that can be obtained with the current and future EHT array for different weather conditions. Results. Our synthetic observations show that the effects of atmospheric and instrumental corruptions on the measured visibilities are significant. Despite these effects, we demonstrate how the overall structure of our GRMHD source models can be recovered robustly with the EHT2017 array after performing calibration steps, which include fringe fitting, a priori amplitude and network calibration, and self-calibration. With the planned addition of new stations to the EHT array in the coming years, images could be reconstr

Published
2020

50. Localizing the γ-ray emitting region in the blazar TXS 2013+370

Author

Traianou, E., primary, Krichbaum, T. P., additional, Boccardi, B., additional, Angioni, R., additional, Rani, B., additional, Liu, J., additional, Ros, E., additional, Bach, U., additional, Sokolovsky, K. V., additional, Lisakov, M. M., additional, Kiehlmann, S., additional, Gurwell, M., additional, and Zensus, J. A., additional

Published
2020
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