8 results on '"Tzioumis, Ak"'
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2. Properties of the Scattering Screen in Front of Scintillating Quasar PKS 1257-326
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Bignall, HE, Jauncey, DL, Lovell, JEJ, Tzioumis, AK, Macquart, JP, Kedziora-Chudczer, L, Bignall, HE, Jauncey, DL, Lovell, JEJ, Tzioumis, AK, Macquart, JP, and Kedziora-Chudczer, L
3. Properties of the Scattering Screen in Front of Scintillating Quasar PKS 1257-326
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Bignall, HE, Jauncey, DL, Lovell, JEJ, Tzioumis, AK, Macquart, JP, Kedziora-Chudczer, L, Bignall, HE, Jauncey, DL, Lovell, JEJ, Tzioumis, AK, Macquart, JP, and Kedziora-Chudczer, L
4. Science with the Australian square kilometre array pathfinder
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Johnston, S, Darling, J, Deller, A, Dodson, R, Edwards, PG, Ekers, R, Ellingsen, SP, Feain, I, Gaensler, BM, Haverkorn, M, Hobbs, G, Bailes, M, Hopkins, A, Jackson, C, James, C, Joncas, G, Kaspi, V, Kilborn, V, Koribalski, B, Kothes, R, Landecker, TL, Lenc, E, Bartel, N, Lovell, JEJ, Macquart, JP, Manchester, RN, Matthews, D, McClure-Griffiths, NM, Norris, Ray, Pen, UL, Phillips, CJ, Power, C, Protheroe, R, Baugh, C, Sadler, E, Schmidt, B, Stairs, I, Staveley-Smith, L, Stil, JM, Taylor, Russell, Tingay, S, Tzioumis, AK, Walker, Mark A, Wall, J, Bietenholz, M, Wolleben, M, Blake, C, Braun, R, Brown, JC, Chatterjee, S, Johnston, S, Darling, J, Deller, A, Dodson, R, Edwards, PG, Ekers, R, Ellingsen, SP, Feain, I, Gaensler, BM, Haverkorn, M, Hobbs, G, Bailes, M, Hopkins, A, Jackson, C, James, C, Joncas, G, Kaspi, V, Kilborn, V, Koribalski, B, Kothes, R, Landecker, TL, Lenc, E, Bartel, N, Lovell, JEJ, Macquart, JP, Manchester, RN, Matthews, D, McClure-Griffiths, NM, Norris, Ray, Pen, UL, Phillips, CJ, Power, C, Protheroe, R, Baugh, C, Sadler, E, Schmidt, B, Stairs, I, Staveley-Smith, L, Stil, JM, Taylor, Russell, Tingay, S, Tzioumis, AK, Walker, Mark A, Wall, J, Bietenholz, M, Wolleben, M, Blake, C, Braun, R, Brown, JC, and Chatterjee, S
- Abstract
The future of centimetre and metre-wave astronomy lies with the Square Kilometre Array (SKA), a telescope under development by a consortium of 17 countries that will be 50 times more sensitive than any existing radio facility. Most of the key science for the SKA will be addressed through large-area imaging of the Universe at frequencies from a few hundred MHz to a few GHz. The Australian SKA Pathfinder (ASKAP) is a technology demonstrator aimed in the mid-frequency range, and achieves instantaneous wide-area imaging through the development and deployment of phased-array feed systems on parabolic reflectors. The large field-of- view makes ASKAP an unprecedented synoptic telescope that will make substantial advances in SKA key science. ASKAP will be located at the Murchison Radio Observatory in inland Western Australia, one of the most radio-quiet locations on the Earth and one of two sites selected by the international community as a potential location for the SKA. In this paper, we outline an ambitious science program for ASKAP, examining key science such as understanding the evolution, formation and population of galaxies including our own, understanding the magnetic Universe, revealing the transient radio sky and searching for gravitational waves.
5. ANTARES constrains a blazar origin of two IceCube PeV neutrino events
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Adrián Martínez, S., Albert, A., André, M., Anton, G., Ardid, M., Aubert, J. J., Baret, B., Barrios, J., Basa, S., Bertin, V., Biagi, S., Bogazzi, C., Bormuth, R., Bou Cabo, M., Bouwhuis, M. C., Bruijn, R., Brunner, J., Busto, J., Capone, Antonio, Caramete, L., Carr, J., Chiarusi, T., Circella, M., Coniglione, R., Core, L., Costantini, H., Coyle, P., Creusot, A., De Rosa, G., Dekeyser, I., Deschamps, A., DE BONIS, Giulia, Distefano, C., Donzaud, C., Dornic, D., Dorosti, Q., Drouhin, D., Dumas, A., Eberl, T., Enzenhöfer, A., Escoffier, S., Fehn, K., Felis, I., Fermani, Paolo, Folger, F., Fusco, L. A., Galatà, S., Gay, P., Geißelsöder, S., Geyer, K., Giordano, V., Gleixner, A., Gřómez González, J. P., Graf, K., Guillard, G., van Haren, H., Heijboer, A. J., Hello, Y., Hernández Rey, J. J., Herold, B., Herrero, A., Hößl, J., Hofestädt, J., Hugon, C., James, C. W., de Jong, M., Kalekin, O., Katz, U., Kießling, D., Kooijman, P., Kouchner, A., Kulikovskiy, V., Lahmann, R., Lambard, E., Lambard, G., Lefèvre, D., Leonora, E., Loehner, H., Loucatos, S., Mangano, S., Marcelin, M., Margiotta, A., Martínez Mora, J. A., Martini, S., Mathieu, A., Michael, T., Migliozzi, P., Neff, M., Nezri, E., Palioselitis, D., Păvăląs, G. E., Pellegrino, C., Perrina, Chiara, Piattelli, P., Popa, V., Pradier, T., Racca, C., Riccobene, G., Richter, R., Roensch, K., Rostovtsev, A., Saldaña, M., Samtleben, D. F. E., Sánchez Losa, . A., Sanguineti, M., Sapienza, P., Schmid, J., Schnabel, J., Schulte, S., Schüssler, F., Seitz, T., Sieger, C., Spies, A., Spurio, M., Steijger, J. J. M., Stolarczyk, T. h., Taiuti, M., Tamburini, C., Tayalati, Y., Trovato, A., Vallage, B., Vallée, C., Van Elewyck, V., Visser, E., Vivolo, D., Wagner, S., de Wolf, E., Yatkin, K., Yepes, H., Zornoza, J. D., Zúñiga, J., Krauß, F., Kadler, M., Mannheim, . K., Schulz, R., Trüstedt, J., Wilms, J., Ojha, R., Ros, E., Baumgartner, W., Beuchert, T., Blanchard, J., Bürkel, C., Carpenter, B., Edwards, P. G., Eisenacher Glawion, D., Elsässer, D., Fritsch, U., Gehrels, N., Gräfe, C., Großberger, C., Hase, H., Horiuchi, S., Kappes, A., Kreikenbohm, A., Kreykenbohm, I., Langejahn, M., Leiter, K., Litzinger, E., Lovell, J. E. J., Müller, C., Phillips, C., Plötz, C., Quick, J., Steinbring, T., Stevens, J., Thompson, D. J., Tzioumis, A. K., Research unit Nuclear & Hadron Physics, Institut d’Investigació per a la Gestió Integrada de Zones Costaneres (IGIC), Universitat Politècnica de València (UPV), Groupe de Recherche en Physique des Hautes Energies (GRPHE), Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut Universitaire de Technologie de Colmar, Laboratory of Applied Bioacoustics (LAB-UPC), Universidad Polytecnica de Cataluña (UPC), Erlangen Centre for Astroparticle Physics (ECAP), Friedrich-Alexander Universität Erlangen-Nürnberg (FAU), Centre de Physique des Particules de Marseille (CPPM), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Aix Marseille Université (AMU), AstroParticule et Cosmologie (APC (UMR_7164)), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7), Laboratoire d'Astrophysique de Marseille (LAM), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES), Laboratoire de Physique Corpusculaire - Clermont-Ferrand (LPC), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut méditerranéen d'océanologie (MIO), Centre National de la Recherche Scientifique (CNRS)-Université de Toulon (UTLN)-Aix Marseille Université (AMU)-Institut de Recherche pour le Développement (IRD), Géoazur (GEOAZUR 7329), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud]), Université Paris-Sud - Paris 11 (UP11), Département de Physique des Particules (ex SPP) (DPP), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Institut Pluridisciplinaire Hubert Curien (IPHC), Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA), The ANTARES Collaboration, The TANAMI Collaboration, Institut Universitaire de Technologie de Colmar-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA)), Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud])-Centre National de la Recherche Scientifique (CNRS)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), KM3NeT (IHEF, IoP, FNWI), Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-IUT de Colmar, Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA)), Aix Marseille Université (AMU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud]), Département de Physique des Particules (ex SPP) (DPhP), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Adrián Martínez, S., Albert, A., André, M., Anton, G., Ardid, M., Aubert, J. J., Baret, B., Barrios, J., Basa, S., Bertin, V., Biagi, S., Bogazzi, C., Bormuth, R., Bou Cabo, M., Bouwhuis, M. C., Bruijn, R., Brunner, J., Busto, J., Capone, A., Caramete, L., Carr, J., Chiarusi, T., Circella, M., Coniglione, R., Costantini, H., Coyle, P., Creusot, A., DE ROSA, Gianfranca, Dekeyser, I., Deschamps, A., De Bonis, G., Distefano, C., Donzaud, C., Dornic, D., Dorosti, Q., Drouhin, D., Dumas, A., Eberl, T., Enzenhöfer, A., Escoffier, S., Fehn, K., Felis, I., Fermani, P., Folger, F., Fusco, L. A., Galatà, S., Gay, P., Geißelsöder, S., Geyer, K., Giordano, V., Gleixner, A., Gómez González, J. P., Gracia Ruiz, R., Graf, K., van Haren, H., Heijboer, A. J., Hello, Y., Hernández Rey, J. J., Herrero, A., Hößl, J., Hofestädt, J., Hugon, C., W. James, C., de Jong, M., Kalekin, O., Katz, U., Kießling, D., Kooijman, P., Kouchner, A., Kulikovskiy, V., Lahmann, R., Lattuada, D., Lefèvre, D., Leonora, E., Loehner, H., Loucatos, S., Mangano, S., Marcelin, M., Margiotta, A., Martínez Mora, J. A., Martini, S., Mathieu, A., Michael, T., Migliozzi, P., Neff, M., Nezri, E., Palioselitis, D., Păvălaş, G. E., Perrina, C., Piattelli, P., Popa, V., Pradier, T., Racca, C., Riccobene, G., Richter, R., Roensch, K., Rostovtsev, A., Saldaña, M., Samtleben, D. F. E., Sánchez Losa, A., Sanguineti, M., Sapienza, P., Schmid, J., Schnabel, J., Schulte, S., Schüssler, F., Seitz, T., Sieger, C., Spies, A., Spurio, M., Steijger, J. J. M., Stolarczyk, T. h., Taiuti, M., Tamburini, C., Tayalati, Y., Trovato, A., Tselengidou, M., Tönnis, C., Vallage, B., Vallée, C., Van Elewyck, V., Visser, E., Vivolo, Daniele, Wagner, S., de Wolf, E., Yepes, H., Zornoza, J. D., Zúñiga, J., Krauß, F., Kadler, M., Mannheim, K., Schulz, R., Trüstedt, J., Wilms, J., Ojha, R., Ros, E., Baumgartner, W., Beuchert, T., Blanchard, J., Bürkel, C., Carpenter, B., Edwards, P. G., Eisenacher Glawion, D., Elsässer, D., Fritsch, U., Gehrels, N., Gräfe, C., Großberger, C., Hase, H., Horiuchi, S., Kappes, A., Kreikenbohm, A., Kreykenbohm, I., Langejahn, M., Leiter, K., Litzinger, E., Lovell, J. E. J., Müller, C., Phillips, C., Plötz, C., Quick, J., Steinbring, T., Stevens, J., Thompson, D. J., Tzioumis, A. K., Adrian-Martinez, S, Albert, A, Andre, M, Anton, G, Ardid, M, Aubert, Jj, Baret, B, Barrios, J, Basa, S, Bertin, V, Biagi, S, Bogazzi, C, Bormuth, R, Bou-Cabo, M, Bouwhuis, Mc, Brujin, R, Brunner, J, Busto, J, Capone, A, Caramete, L, Cane, J, Chiarusim, T, Circella, M, Coniglione, R, Costantini, H, Coyle, P, Creusot, A, De Rosa, G, Dekeyser, I, Deschamps, A, De Bonis, G, Distefano, C, Donzaud, C, Dornic, D, Dorosti, Q, Drouhin, D, Dumas, A, Eberl, T, Enzenhofer, A, Escoffier, S, Fehn, K, Felis, I, Fermani, P, Folger, F, Fusco, La, Galata, S, Gay, P, Geisselsoder, S, Geyer, K, Giordano, V, Gleixner, A, Gomez-Gonzalez, Jp, Gracia-Ruiz, R, Graf, K, van Haren, H, Heijboer, Aj, Hello, Y, Hernandez-Rey, Jj, Herrero, A, Hossl, J, Hofestadt, J, Hugon, C, James, Cw, de Jong, M, Kalekin, O, Katz, U, Kiessling, D, Kooijman, P, Kouchner, A, Kulikovskiy, V, Lahmann, R, Lattuada, D, Lefevre, D, Leonora, E, Loehner, H, Loucatos, S, Mangano, S, Marcelin, M, Margiotta, A, Martinez-Mora, Ja, Martini, S, Mathieu, A, Michael, T, Migliozzi, P, Neff, M, Nezri, E, Palioselitis, D, Pavalas, Ge, Perrina, C, Piattelli, P, Popa, V, Pradier, T, Racca, C, Riccobene, G, Richter, R, Roensch, K, Rostovtsev, A, Saldana, M, Samtleben, Dfe, Sanchez-Losa, A, Sanguineti, M, Sapienza, P, Schmid, J, Schnabel, J, Schulte, S, Schussler, F, Seitz, T, Sieger, C, Spies, A, Spurio, M, Steijger, Jjm, Stolarczyk, T, Taiuti, M, Tamburini, C, Tayalati, Y, Trovato, A, Tselengidou, M, Tonnis, C, Vallage, B, Vallee, C, Van Elewyck, V, Visser, E, Vivolo, D, Wagner, S, de Wolf, E, Yepes, H, Zornoza, Jd, Zuniga, J, Krauss, F, Kadler, M, Mannheim, K, Schulz, R, Trustedt, J, Wilms, J, Ojha, R, Ros, E, Baumgartner, W, Beuchert, T, Blanchard, J, Burke, C, Carpenter, B, Edwards, Pg, Glawion, De, Elsasser, D, Fritsch, U, Gehrels, N, Grafe, C, Grossberger, C, Hase, H, Horiuchi, S, Kappes, A, Kreikenbohm, A, Kreykenbohm, I, Langejahn, M, Leiter, K, Litzinger, E, Lovell, Jej, Muller, C, Phillips, C, Plotz, C, Quick, J, Steinbring, T, Stevens, J, Thompson, Dj, Tzioumis, Ak, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Université de Strasbourg (UNISTRA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Adrián-Martínez, S, Aubert, J.-J., Bou-Cabo, M., Bouwhuis, M.C., De Rosa, G., Fusco, L.A., Gómez-González, J.P., Gracia-Ruiz, R., Van Haren, H., Heijboer, A.J., Hernández-Rey, J.J., James, C.W., De Jong, M., Martínez-Mora, J.A., Pəvəlaş, G.E., Samtleben, D.F.E., Sánchez-Losa, A., Steijger, J.J.M., Stolarczyk, Th., Vivolo, D., De Wolf, E., Zornoza, J.D., Edwards, P.G., Lovell, J.E.J., Thompson, D.J., Tzioumis, A.K., Centre Tecnològic de Vilanova i la Geltrú, Universitat Politècnica de Catalunya. LAB - Laboratori d'Aplicacions Bioacústiques, Adrian-Martinez, S., Andre, M., Aubert, J. -J., Enzenhofer, A., Galata, S., Geisselsoder, S., Gomez-Gonzalez, J. P., Hernandez-Rey, J. J., Hossl, J., Hofestadt, J., James, C. W., Kiessling, D., Lefevre, D., Martinez-Mora, J. A., Pevelas, G. E., Saldana, M., Sanchez-Losa, A., Schussler, F., Tonnis, C., Vallee, C., Zuniga, J., Krauss, F., Trustedt, J., Burkel, C., Elsasser, D., Grafe, C., Grossberger, C., Muller, C., and Plotz, C.
- Subjects
Astrofísica ,active [Galaxies] ,Astrophysics::High Energy Astrophysical Phenomena ,Monte Carlo method ,Flux ,FOS: Physical sciences ,Cosmic ray ,Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,7. Clean energy ,01 natural sciences ,Spectral line ,0103 physical sciences ,Neutrino ,Galaxies: active ,Neutrinos ,Quasars: general ,Neutrins ,Blazar ,010303 astronomy & astrophysics ,Physics ,High Energy Astrophysical Phenomena (astro-ph.HE) ,Muon ,Cosmologia ,010308 nuclear & particles physics ,Física ,Astronomy and Astrophysics ,general [Quasars] ,Astronomy and Astrophysic ,Neutrino astrophysics ,Quasars general ,Cosmology ,neutrinos – galaxies: active – quasars: general ,Space and Planetary Science ,Galaxies active ,Col·lisions (Física nuclear) ,Física::Astronomia i astrofísica [Àrees temàtiques de la UPC] ,FISICA APLICADA ,Física nuclear ,Astrophysics - High Energy Astrophysical Phenomena ,MATEMATICA APLICADA ,[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph] ,Event (particle physics) - Abstract
Context. The source(s) of the neutrino excess reported by the IceCube Collaboration is unknown. The TANAMI Collaboration recently reported on the multiwavelength emission of six bright, variable blazars which are positionally coincident with two of the most energetic IceCube events. Objects like these are prime candidates to be the source of the highest-energy cosmic rays, and thus of associated neutrino emission. Aims. We present an analysis of neutrino emission from the six blazars using observations with the ANTARES neutrino telescope. Methods. The standard methods of the ANTARES candidate list search are applied to six years of data to search for an excess of muons and hence their neutrino progenitors from the directions of the six blazars described by the TANAMI Collaboration, and which are possibly associated with two IceCube events. Monte Carlo simulations of the detector response to both signal and background particle fluxes are used to estimate the sensitivity of this analysis for different possible source neutrino spectra. A maximum-likelihood approach, using the reconstructed energies and arrival directions of through-going muons, is used to identify events with properties consistent with a blazar origin. Results. Both blazars predicted to be the most neutrino-bright in the TANAMI sample (1653-329 and 1714-336) have a signal flux fitted by the likelihood analysis corresponding to approximately one event. This observation is consistent with the blazar-origin hypothesis of the IceCube event IC 14 for a broad range of blazar spectra, although an atmospheric origin cannot be excluded. No ANTARES events are observed from any of the other four blazars, including the three associated with IceCube event IC20. This excludes at a 90% confidence level the possibility that this event was produced by these blazars unless the neutrino spectrum is flatter than -2.4., The authors would like to thank A. Kappes for helpful discussions regarding the IceCube analysis. The ANTARES authors acknowledge the financial support of the funding agencies: Centre National de la Recherche Scientifique (CNRS), Commissariat a l'enegie atomique et aux energies alternatives (CEA), Commission Europeenne (FEDER fund and Marie Curie Program), Region Alsace (contrat CPER), Region Provence-Alpes-Cote d'Azur, Departement du Var and Ville de La Seyne-sur-Mer, France; Bundesministerium fur Bildung und Forschung (BMBF), Germany; Istituto Nazionale di Fisica Nucleare (INFN), Italy; Stichting voor Fundamenteel Onderzoek der Materie (FOM), Nederlandse organisatie voor Wetenschappelijk Onderzoek (NWO), the Netherlands; Council of the President of the Russian Federation for young scientists and leading scientific schools supporting grants, Russia; National Authority for Scientific Research (ANCS), Romania; Ministerio de Ciencia e Innovacion (MICINN), Prometeo of Generalitat Valenciana and MultiDark, Spain; Agence de l'Oriental and CNRST, Morocco. We also acknowledge the technical support of Ifremer, AIM and Foselev Marine for the sea operation and the CC-IN2P3 for the computing facilities. The TANAMI authors acknowledge support and partial funding by the Deutsche Forschungsgemeinschaft grant WI 1860-10/1 (TANAMI) and GRK 1147, Deutsches Zentrum fur Luft- und Raumfahrt grant 50 OR1311/50 OR1303/50 OR1401, the Spanish MINECO project AYA2012-38491-C02-01, the Generalitat Valenciana project PROMETEOII/2014/057, the COST MP0905 action "Black Holes in a Violent Universe" and the Helmholtz Alliance for Astroparticle Physics (HAP).
- Published
- 2015
6. Nine-hour X-ray quasi-periodic eruptions from a low-mass black hole galactic nucleus.
- Author
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Miniutti G, Saxton RD, Giustini M, Alexander KD, Fender RP, Heywood I, Monageng I, Coriat M, Tzioumis AK, Read AM, Knigge C, Gandhi P, Pretorius ML, and Agís-González B
- Abstract
In the past two decades, high-amplitude electromagnetic outbursts have been detected from dormant galaxies and often attributed to the tidal disruption of a star by the central black hole
1,2 . X-ray emission from the Seyfert 2 galaxy GSN 069 (2MASX J01190869-3411305) at a redshift of z = 0.018 was first detected in July 2010 and implies an X-ray brightening by a factor of more than 240 over ROSAT observations performed 16 years earlier3,4 . The emission has smoothly decayed over time since 2010, possibly indicating a long-lived tidal disruption event5 . The X-ray spectrum is ultra-soft and can be described by accretion disk emission with luminosity proportional to the fourth power of the disk temperature during long-term evolution. Here we report observations of quasi-periodic X-ray eruptions from the nucleus of GSN 069 over the course of 54 days, from December 2018 onwards. During these eruptions, the X-ray count rate increases by up to two orders of magnitude with an event duration of just over an hour and a recurrence time of about nine hours. These eruptions are associated with fast spectral transitions between a cold and a warm phase in the accretion flow around a low-mass black hole (of approximately 4 × 105 solar masses) with peak X-ray luminosity of about 5 × 1042 erg per second. The warm phase has kT (where T is the temperature and k is the Boltzmann constant) of about 120 electronvolts, reminiscent of the typical soft-X-ray excess, an almost universal thermal-like feature in the X-ray spectra of luminous active nuclei6-8 . If the observed properties are not unique to GSN 069, and assuming standard scaling of timescales with black hole mass and accretion properties, typical active galactic nuclei with higher-mass black holes can be expected to exhibit high-amplitude optical to X-ray variability on timescales as short as months or years9 .- Published
- 2019
- Full Text
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7. Large-scale, decelerating, relativistic x-ray jets from the microquasar XTE J1550-564.
- Author
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Corbel S, Fender RP, Tzioumis AK, Tomsick JA, Orosz JA, Miller JM, Wijnands R, and Kaaret P
- Abstract
We have detected, at x-ray and radio wavelengths, large-scale moving jets from the microquasar XTE J1550-564. Plasma ejected from near the black hole traveled at relativistic velocities for at least 4 years. We present direct evidence for gradual deceleration in a relativistic jet. The broadband spectrum of the jets is consistent with synchrotron emission from high-energy (up to 10 tera-electron volts) particles that were accelerated in the shock waves formed within the relativistic ejecta or by the interaction of the jets with the interstellar medium. XTE J1550-564 offers a rare opportunity to study the dynamical evolution of relativistic jets on time scales inaccessible for active galactic nuclei jets, with implications for our understanding of relativistic jets from Galactic x-ray binaries and active galactic nuclei.
- Published
- 2002
- Full Text
- View/download PDF
8. Subparsec-scale structure and evolution of Centaurus A (NGC5128).
- Author
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Jauncey DL, Tingay SJ, Preston RA, Reynolds JE, Lovell JE, McCulloch PM, Tzioumis AK, Costa ME, Murphy DW, Meier DL, Jones DL, Amy SW, Biggs JD, Blair DG, Clay RW, Edwards PG, Ellingsen SP, Ferris RH, Gough RG, Harbison P, Jones PA, King EA, Kemball AJ, Migenes V, Nicolson GD, Sinclair MW, Van Ommen T, Wark RM, and White GL
- Abstract
We present a series of 8.4-GHz very-long-baseline radio interferometry images of the nucleus of Centaurus A (NGC5128) made with a Southern Hemisphere array, representing a 3.3-year monitoring effort. The nuclear radio jet is approximately 50 milliarcseconds in extent, or at the 3.5-megaparsec distance of NGC5128, approximately 1 parsec in length. Subluminal motion is seen and structural changes are observed on time scales shorter than 4 months. High-resolution observations at 4.8 and 8.4 GHz made in November 1992 reveal a complex morphology and allow us to unambiguously identify the self-absorbed core located at the southwestern end of the jet.
- Published
- 1995
- Full Text
- View/download PDF
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