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29 results on '"24420530 - Böttcher, Markus"'

1. Millimeter-Wave Monitoring of Active Galactic Nuclei with the Africa Millimetre Telescope

Author: Michael Backes, Markus Böttcher, Heino Falcke, 28644743 - Backes, Michael, and 24420530 - Böttcher, Markus
Subjects: Active galactic nucleus, Monitoring, lcsh:Astronomy, Astronomy, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Cosmic ray, Astrophysics::Cosmology and Extragalactic Astrophysics, 7. Clean energy, 01 natural sciences, law.invention, Radio telescope, Telescope, lcsh:QB1-991, law, 0103 physical sciences, mm-VLBI, 010303 astronomy & astrophysics, Millimeter-wave astronomy, Instrumentation and Methods for Astrophysics (astro-ph.IM), Astrophysics::Galaxy Astrophysics, Event Horizon Telescope, Physics, High Energy Astrophysical Phenomena (astro-ph.HE), Active galactic nuclei, 010308 nuclear & particles physics, Gamma ray, Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy and Astrophysics, Galaxy, monitoring, Extremely high frequency, active galactic nuclei, millimeter-wave astronomy, Astrophysics::Earth and Planetary Astrophysics, Astrophysics - Instrumentation and Methods for Astrophysics, Astrophysics - High Energy Astrophysical Phenomena
Abstract: Active Galactic Nuclei are the dominant sources of gamma rays outside our Galaxy and also candidates for being the source of ultra-high energy cosmic rays. In addition to being emitters of broad-band non-thermal radiation throughout the electromagnetic spectrum, their emission is highly variable on timescales from years to minutes. Hence, high-cadence monitoring observations are needed to understand their emission mechanisms. The Africa Millimetre Telescope is planned to be the first mm-wave radio telescope on the African continent and one of few in the Southern hemisphere. Further to contributing to the global mm-VLBI observations with the Event Horizon Telescope, substantial amounts of observation time will be available for monitoring observations of Active Galactic Nuclei. Here we review the scientific scope of the Africa Millimetre Telescope for monitoring of Active Galactic Nuclei at mm-wavelengths., Comment: Accepted for publication in Galaxies, Special Issue "Monitoring the Non-Thermal Universe": https://www.mdpi.com/journal/galaxies/special_issues/non-thermalUniverse
Published: 2019

2. Optical Variability Modelling Of Newly Identified Blazars And Blazar Candidates Behind Magellanic Clouds

Author: Volodymyr Marchenko, Markus Böttcher, Łukasz Stawarz, Natalia Zywucka, Mariusz Tarnopolski, 34208968 - Zywucka-Hejzner, Natalia, and 24420530 - Böttcher, Markus
Subjects: Physics, Hurst exponent, Active galactic nuclei, Spectral density, Quasar, Astrophysics, Light curve, Power law, Gravitational lens, Active galaxies, BL Lacertae objects, Magellanic Clouds, Small Magellanic Cloud, Blazar, Large Magellanic Cloud, Line (formation)
Abstract: We present results of a variability study in the optical band of 44 newly identified blazar candidates behind the Magellanic Clouds. Our sample contains 27 flat spectrum radio quasars (FSRQs) and 17 BL Lacertae objects (BL Lacs). However, only nine of them are considered as secure blazar candidates, while the classification of the remaining 35 objects is still uncertain. All studied blazar candidates possess infrequently sampled optical light curves (LCs) in I filter provided by the Optical Gravitational Lensing Experiment group. The LCs were analysed with the Lomb-Scargle periodogram, the Hurst exponent $H$, and the $\mathcal{A}-\mathcal{T}$ plane, to look for blazar-like characteristic features and to study the long-term behaviour of the optical fluxes. The power law (PL) indices of the Lomb-Scargle power spectral density (PSD) of the FSRQ blazar candidates mostly lie in the range $(1,2)$. In case of the BL Lacs they are located in the range $(1,1.8)$. The PL PSD is indicative of a self-affine stochastic process characterised by $H$, underlying the observed variability. We find that the majority of analysed objects have $H\leq 0.5$, indicating short-term memory, whereas four BL Lacs and two FSRQs have $H>0.5$, implying long-term memory. 41 blazar candidates are located in the $\mathcal{A}-\mathcal{T}$ plane in the region available to PL plus Poisson noise processes. Interestingly, one FSRQ is located marginally below this region, while two FSRQs lie above the line $\mathcal{T}=2/3$, i.e. they are even more noisy than white noise. The BL Lac candidates are characterised by higher $\mathcal{A}$ values than FSRQs, i.e. $0.71\pm 0.06$ and $0.29\pm 0.05$, respectively.
Published: 2020
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3. gSeaGen: The KM3NeT GENIE-based code for neutrino telescopes

Author: Jutta Schnabel, S. Reck, G. Vannoye, L. Maderer, D. van Eijk, J. Brunner, Rosanna Cocimano, Fabio Longhitano, D. Guderian, F. Versari, Kay Graf, Karel Melis, P. Migliozzi, C. Pastore, Diego Real, A. Franco, Zineb Aly, J. Reubelt, M. Perrin-Terrin, Carlo Alessandro Nicolau, Natalia Zywucka, G. Papalashvili, V. Sciacca, G. de Wasseige, Karl Mannheim, Piotr Kalaczyński, A. Martini, Z. Modebadze, M. De Palma, A. Enzenhöfer, R. Coniglione, Giuseppina Larosa, Daniele Vivolo, O. Gabella, Giuseppe Levi, J. Hofestädt, Soebur Razzaque, Paolo Fermani, Jihad Boumaaza, Luigi Antonio Fusco, S. Mastroianni, M. Organokov, B. Ó Fearraigh, N. R. Khan Chowdhury, W. Idrissi Ibnsalih, Simona Maria Stellacci, Ofelia Pisanti, Nhan Chau, S. Mazzou, M. Taiuti, M. de Jong, Gisela Anton, Alessia Capone, Carlos Maximiliano Mollo, P.M. Kooijman, Vitaliano Chiarella, M. Lindsey Clark, F. Garufi, Alice Paun, M. Ardid, Jose Busto, Tommaso Chiarusi, Paolo Castaldi, I. Sgura, T. Thakore, G.E. Păvălaş, A. Garcia Soto, E. Tzamariudaki, Thierry Pradier, S. Rivoire, S. Sánchez Navas, M. Bouta, Ornella Leonardi, Sara Pulvirenti, E. Berbee, Angelo Orlando, J. Seneca, Matthias Kadler, Joao A B Coelho, Mancia Anguita, Massimiliano Lincetto, L. Martin, Annarita Margiotta, Silvia Celli, O. Kalekin, V. Espinosa Roselló, I. El Bojaddaini, Richard Dallier, L. S. Miranda, Michel André, Andrea Santangelo, R. Le Breton, Thomas Eberl, M. Bissinger, G. Pühlhofer, A. Sharma, Dídac Diego-Tortosa, A.M. van den Berg, V. Van Elewyck, Robert Lahmann, Francesco Leone, R. Muller, S. R. Gozzini, E. Tenllado, F. Filippini, Bouke Jisse Jung, Vladimir Kulikovskiy, M. Post, Giulia Illuminati, M. Morganti, R. Donà, S.F. Biagi, E. A. De Wolf, P. Coyle, J. Manczak, Corinne Donzaud, I. Corredoira, Alexis Coleiro, Giacomo Cuttone, T. Lipreau, C. Guidi, E. Buis, S. Basegmez du Pree, Miroslav Filipovic, O. Rabyang, J. Aublin, P. Mijakowski, Damien Dornic, Jos Steijger, Bruny Baret, Sebastiano Aiello, S. Alves Garre, A. W. Chen, R. Bruijn, Riccardo Papaleo, L. Quinn, H. van Haren, G. Grella, A. Rapicavoli, K. Pikounis, G. Androulakis, G. C. Barbarino, Silvio Cherubini, J.J. Hernández-Rey, Yahya Tayalati, M. Bendahman, C. Bagatelas, Alessandro Lonardo, T. Gal, C. Distefano, D. F. E. Samtleben, A. Hekalo, Mora Durocher, U. Katz, M. Anghinolfi, A. Sinopoulou, Sandra Zavatarelli, H. Brânzaş, Mario Musumeci, S. Viola, N. Randazzo, E. Migneco, B. Spisso, M. Richer, H. Hamdaoui, M. Circella, D. Zaborov, Andrea Biagioni, L. Nauta, Matteo Sanguineti, R. Wojaczyński, G. Ferrara, G. Riccobene, R. Gracia, Els Koffeman, V. Bertin, D. Drouhin, Fabio Marzaioli, F. Raffaelli, Markus Boettcher, F. Huang, C. Poirè, P. Piattelli, Antonio D'Onofrio, Jörn Wilms, Emanuele Leonora, Mohamed Chabab, M. Bruchner, Arnauld Albert, F. van der Knaap, C. Markou, D. Tzanetatos, Cristiano Bozza, Lucio Gialanella, G. Vasileiadis, F. Salesa Greus, J.D. Zornoza, Y. Gatelet, Steven Tingay, V. Carretero, Domenico Santonocito, Michael Moser, C. Pieterse, C. W. James, Antoine Kouchner, A. Zegarelli, Paolo Sapienza, M. Colomer Molla, Dominik Elsaesser, C. Pellegrino, P. de Jong, D. Stavropoulos, A. Rovelli, Abdelilah Moussa, Michael Kreter, A. Marinelli, N. Geißelbrecht, A. Sánchez Losa, A. Creusot, Maurizio Spurio, A.J. Heijboer, M.C. Bouwhuis, Raffaele Buompane, Gennaro Miele, Alba Domi, D. Calvo, I. Di Palma, Antonio F. Díaz, J. Zúñiga, D. Lopez-Coto, J.A. Martínez-Mora, Dario Grasso, Fabrizio Ameli, V. Popa, Francesco Simeone, Emidio Giorgio, Steffen Hallmann, M. Dörr, Rezo Shanidze, Ministerio de Ciencia e Innovación (España), Generalitat Valenciana, 24420530 - Böttcher, Markus, 33379009 - Kreter, Michael, 34208968 - Zywucka-Hejzner, Natalia, 27743268 - Rabyang, O., Centre Tecnològic de Vilanova i la Geltrú, Universitat Politècnica de Catalunya. LAB - Laboratori d'Aplicacions Bioacústiques, Aiello S., Albert A., Garre S.A., Aly Z., Ameli F., Andre M., Androulakis G., Anghinolfi M., Anguita M., Anton G., Ardid M., Aublin J., Bagatelas C., Barbarino G., Baret B., Basegmez du Pree S., Bendahman M., Berbee E., van den Berg A.M., Bertin V., Biagi S., Biagioni A., Bissinger M., Boettcher M., Boumaaza J., Bouta M., Bouwhuis M., Bozza C., Branzas H., Bruchner M., Bruijn R., Brunner J., Buis E., Buompane R., Busto J., Calvo D., Capone A., Carretero V., Castaldi P., Celli S., Chabab M., Chau N., Chen A., Cherubini S., Chiarella V., Chiarusi T., Circella M., Cocimano R., Coelho J.A.B., Coleiro A., Molla M.C., Coniglione R., Corredoira I., Coyle P., Creusot A., Cuttone G., D'Onofrio A., Dallier R., De Palma M., Di Palma I., Diaz A.F., Diego-Tortosa D., Distefano C., Domi A., Dona R., Donzaud C., Dornic D., Dorr M., Drouhin D., Durocher M., Eberl T., van Eijk D., El Bojaddaini I., Elsaesser D., Enzenhofer A., Rosello V.E., Fermani P., Ferrara G., Filipovic M.D., Filippini F., Franco A., Fusco L.A., Gabella O., Gal T., Soto A.G., Garufi F., Gatelet Y., Geisselbrecht N., Gialanella L., Giorgio E., Gozzini S.R., Gracia R., Graf K., Grasso D., Grella G., Guderian D., Guidi C., Hallmann S., Hamdaoui H., van Haren H., Heijboer A., Hekalo A., Hernandez-Rey J.J., Hofestadt J., Huang F., Ibnsalih W.I., Illuminati G., James C.W., de Jong M., de Jong P., Jung B.J., Kadler M., Kalaczynski P., Kalekin O., Katz U.F., Chowdhury N.R.K., van der Knaap F., Koffeman E.N., Kooijman P., Kouchner A., Kreter M., Kulikovskiy V., Lahmann R., Larosa G., Le Breton R., Leonardi O., Leone F., Leonora E., Levi G., Lincetto M., Lindsey Clark M., Lipreau T., Lonardo A., Longhitano F., Lopez-Coto D., Maderer L., Manczak J., Mannheim K., Margiotta A., Marinelli A., Markou C., Martin L., Martinez-Mora J.A., Martini A., Marzaioli F., Mastroianni S., Mazzou S., Melis K.W., Miele G., Migliozzi P., Migneco E., Mijakowski P., Miranda L.S., Modebadze Z., Mollo C.M., Morganti M., Moser M., Moussa A., Muller R., Musumeci M., Nauta L., Navas S., Nicolau C.A., O Fearraigh B., Organokov M., Orlando A., Papalashvili G., Papaleo R., Pastore C., Paun A.M., Pavalas G.E., Pellegrino C., Perrin-Terrin M., Piattelli P., Pieterse C., Pikounis K., Pisanti O., Poire C., Popa V., Post M., Pradier T., Puhlhofer G., Pulvirenti S., Quinn L., Rabyang O., Raffaelli F., Randazzo N., Rapicavoli A., Razzaque S., Real D., Reck S., Reubelt J., Riccobene G., Richer M., Rivoire S., Rovelli A., Greus F.S., Samtleben D.F.E., Losa A.S., Sanguineti M., Santangelo A., Santonocito D., Sapienza P., Schnabel J., Sciacca V., Seneca J., Sgura I., Shanidze R., Sharma A., Simeone F., Sinopoulou A., Spisso B., Spurio M., Stavropoulos D., Steijger J., Stellacci S.M., Taiuti M., Tayalati Y., Tenllado E., Thakore T., Tingay S., Tzamariudaki E., Tzanetatos D., Van Elewyck V., Vannoye G., Vasileiadis G., Versari F., Viola S., Vivolo D., de Wasseige G., Wilms J., Wojaczynski R., de Wolf E., Zaborov D., Zavatarelli S., Zegarelli A., Zornoza J.D., Zuniga J., Zywucka N., Institut Pluridisciplinaire Hubert Curien (IPHC), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), 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, Centre de Physique des Particules de Marseille (CPPM), Aix Marseille Université (AMU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), AstroParticule et Cosmologie (APC (UMR_7164)), 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)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Laboratoire de physique subatomique et des technologies associées (SUBATECH), Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT), Laboratoire Univers et Particules de Montpellier (LUPM), Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Montpellier 2 - Sciences et Techniques (UM2), Institut Universitaire de France (IUF), Ministère de l'Education nationale, de l’Enseignement supérieur et de la Recherche (M.E.N.E.S.R.), KM3NeT, 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), 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)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-IMT Atlantique (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-Nantes université - UFR des Sciences et des Techniques (Nantes univ - UFR ST), Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ)-Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), ANR-15-CE31-0020,DAEMONS,Démonstration de la possibilité d'établir l'ordonnancement des masses de neutrinos dans la mer(2015), ANR-10-LABX-0023,UnivEarthS,Earth - Planets - Universe: observation, modeling, transfer(2010), ANR-11-IDEX-0005,USPC,Université Sorbonne Paris Cité(2011), Aiello, S., Albert, A., Garre, S. A., Aly, Z., Ameli, F., Andre, M., Androulakis, G., Anghinolfi, M., Anguita, M., Anton, G., Ardid, M., Aublin, J., Bagatelas, C., Barbarino, G., Baret, B., Basegmez du Pree, S., Bendahman, M., Berbee, E., van den Berg, A. M., Bertin, V., Biagi, S., Biagioni, A., Bissinger, M., Boettcher, M., Boumaaza, J., Bouta, M., Bouwhuis, M., Bozza, C., Branzas, H., Bruchner, M., Bruijn, R., Brunner, J., Buis, E., Buompane, R., Busto, J., Calvo, D., Capone, A., Carretero, V., Castaldi, P., Celli, S., Chabab, M., Chau, N., Chen, A., Cherubini, S., Chiarella, V., Chiarusi, T., Circella, M., Cocimano, R., Coelho, J. A. B., Coleiro, A., Molla, M. C., Coniglione, R., Corredoira, I., Coyle, P., Creusot, A., Cuttone, G., D'Onofrio, A., Dallier, R., De Palma, M., Di Palma, I., Diaz, A. F., Diego-Tortosa, D., Distefano, C., Domi, A., Dona, R., Donzaud, C., Dornic, D., Dorr, M., Drouhin, D., Durocher, M., Eberl, T., van Eijk, D., El Bojaddaini, I., Elsaesser, D., Enzenhofer, A., Rosello, V. E., Fermani, P., Ferrara, G., Filipovic, M. D., Filippini, F., Franco, A., Fusco, L. A., Gabella, O., Gal, T., Soto, A. G., Garufi, F., Gatelet, Y., Geisselbrecht, N., Gialanella, L., Giorgio, E., Gozzini, S. R., Gracia, R., Graf, K., Grasso, D., Grella, G., Guderian, D., Guidi, C., Hallmann, S., Hamdaoui, H., van Haren, H., Heijboer, A., Hekalo, A., Hernandez-Rey, J. J., Hofestadt, J., Huang, F., Ibnsalih, W. I., Illuminati, G., James, C. W., de Jong, M., de Jong, P., Jung, B. J., Kadler, M., Kalaczynski, P., Kalekin, O., Katz, U. F., Chowdhury, N. R. K., van der Knaap, F., Koffeman, E. N., Kooijman, P., Kouchner, A., Kreter, M., Kulikovskiy, V., Lahmann, R., Larosa, G., Le Breton, R., Leonardi, O., Leone, F., Leonora, E., Levi, G., Lincetto, M., Lindsey Clark, M., Lipreau, T., Lonardo, A., Longhitano, F., Lopez-Coto, D., Maderer, L., Manczak, J., Mannheim, K., Margiotta, A., Marinelli, A., Markou, C., Martin, L., Martinez-Mora, J. A., Martini, A., Marzaioli, F., Mastroianni, S., Mazzou, S., Melis, K. W., Miele, G., Migliozzi, P., Migneco, E., Mijakowski, P., Miranda, L. S., Modebadze, Z., Mollo, C. M., Morganti, M., Moser, M., Moussa, A., Muller, R., Musumeci, M., Nauta, L., Navas, S., Nicolau, C. A., O Fearraigh, B., Organokov, M., Orlando, A., Papalashvili, G., Papaleo, R., Pastore, C., Paun, A. M., Pavalas, G. E., Pellegrino, C., Perrin-Terrin, M., Piattelli, P., Pieterse, C., Pikounis, K., Pisanti, O., Poire, C., Popa, V., Post, M., Pradier, T., Puhlhofer, G., Pulvirenti, S., Quinn, L., Rabyang, O., Raffaelli, F., Randazzo, N., Rapicavoli, A., Razzaque, S., Real, D., Reck, S., Reubelt, J., Riccobene, G., Richer, M., Rivoire, S., Rovelli, A., Greus, F. S., Samtleben, D. F. E., Losa, A. S., Sanguineti, M., Santangelo, A., Santonocito, D., Sapienza, P., Schnabel, J., Sciacca, V., Seneca, J., Sgura, I., Shanidze, R., Sharma, A., Simeone, F., Sinopoulou, A., Spisso, B., Spurio, M., Stavropoulos, D., Steijger, J., Stellacci, S. M., Taiuti, M., Tayalati, Y., Tenllado, E., Thakore, T., Tingay, S., Tzamariudaki, E., Tzanetatos, D., Van Elewyck, V., Vannoye, G., Vasileiadis, G., Versari, F., Viola, S., Vivolo, D., de Wasseige, G., Wilms, J., Wojaczynski, R., de Wolf, E., Zaborov, D., Zavatarelli, S., Zegarelli, A., Zornoza, J. D., Zuniga, J., Zywucka, N., KM3NeT (IHEF, IoP, FNWI), ATLAS (IHEF, IoP, FNWI), and Research unit Astroparticle Physics
Subjects: Astrofísica, Physics::Instrumentation and Detectors, General Physics and Astronomy, Neutrino telescope, Astrophysics, 01 natural sciences, 010305 fluids & plasmas, astro-ph.IMA, Monte Carlo event generator, KM3NeT, neutrino: interaction, [PHYS]Physics [physics], Physics, density, 4. Education, Neutrino oscillations, Detector, neutrino: detector, Neutrino detector, statistics, Hardware and Architecture, neutrino: flavor, Neutrino, Astrophysics - Instrumentation and Methods for Astrophysics, Particle physics, Neutrino oscillation, Astrophysics::High Energy Astrophysical Phenomena, Astroparticle physics, High energy neutrinos, Neutrino telescopes, GENIE, FOS: Physical sciences, Physique [physics]/Physique [physics], Astroparticle physic, topological, 0103 physical sciences, Code (cryptography), [PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det], Neutrins, 010306 general physics, Instrumentation and Methods for Astrophysics (astro-ph.IM), Telescopis, High Energy Physics::Phenomenology, High energy neutrino, stroparticle physics, astro-ph.IM, high energy neutrinos, FISICA APLICADA, Física::Astronomia i astrofísica [Àrees temàtiques de la UPC], High Energy Physics::Experiment, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Telescopes
Abstract: Program summary Program Title: gSeaGen CPC Library link to program files: http://dx.doi.org/10.17632/ymgxvy2br4.1 Licensing provisions: GPLv3 Programming language: C++ External routines/libraries: GENIE [1] and its external dependencies. Linkable to MUSIC [2] and PROPOSAL [3]. Nature of problem: Development of a code to generate detectable events in neutrino telescopes, using modern and maintained neutrino interaction simulation libraries which include the state-of-the-art physics models. The default application is the simulation of neutrino interactions within KM3NeT [4]. Solution method: Neutrino interactions are simulated using GENIE, a modern framework for Monte Carlo event generators. The GENIE framework, used by nearly all modern neutrino experiments, is considered as a reference code within the neutrino community. Additional comments including restrictions and unusual features: The code was tested with GENIE version 2.12.10 and it is linkable with release series 3. Presently valid up to 5 TeV. This limitation is not intrinsic to the code but due to the present GENIE valid energy range. References: [1] C. Andreopoulos at al., Nucl. Instrum. Meth. A614 (2010) 87. [2] P. Antonioli et al., Astropart. Phys. 7 (1997) 357. [3] J. H. Koehne et al., Comput. Phys. Commun. 184 (2013) 2070. [4] S. Adrián-Martínez et al., J. Phys. G: Nucl. Part. Phys. 43 (2016) 084001., The gSeaGen code is a GENIE-based application developed to efficiently generate high statistics samples of events, induced by neutrino interactions, detectable in a neutrino telescope. The gSeaGen code is able to generate events induced by all neutrino flavours, considering topological differences between tracktype and shower-like events. Neutrino interactions are simulated taking into account the density and the composition of the media surrounding the detector. The main features of gSeaGen are presented together with some examples of its application within the KM3NeT project., French National Research Agency (ANR) ANR-15-CE31-0020, Centre National de la Recherche Scientifique (CNRS), European Union (EU), Institut Universitaire de France (IUF), France, IdEx program, France, UnivEarthS Labex program at Sorbonne Paris Cite ANR-10-LABX-0023 ANR-11-IDEX-000502, Paris Ile-de-France Region, France, Shota Rustaveli National Science Foundation of Georgia (SRNSFG), Georgia FR-18-1268, German Research Foundation (DFG), Greek Ministry of Development-GSRT, Istituto Nazionale di Fisica Nucleare (INFN), Ministry of Education, Universities and Research (MIUR), PRIN 2017 program Italy NAT-NET 2017W4HA7S, Ministry of Higher Education, Scientific Research and Professional Training, Morocco, Netherlands Organization for Scientific Research (NWO) Netherlands Government, National Science Centre, Poland 2015/18/E/ST2/00758, National Authority for Scientific Research (ANCS), Romania, Ministerio de Ciencia, Innovacion, Investigacion y Universidades (MCIU): Programa Estatal de Generacion de Conocimiento, Spain (MCIU/FEDER) PGC2018-096663-B-C41 PGC2018-096663-A-C42 PGC2018-096663-BC43 PGC2018-096663-B-C44, Severo Ochoa Centre of Excellence and MultiDark Consolider (MCIU), Junta de Andalucia, Spain SOMM17/6104/UGR, Generalitat Valenciana: Grisolia, Spain GRISOLIA/2018/119, GenT, Spain CIDEGENT/2018/034, La Caixa Foundation LCF/BQ/IN17/11620019, EU: MSC program, Spain 713673
Published: 2020
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4. Multifrequency observations of the candidate neutrino-emitting blazar BZB J0955+3551

Author: S. Garrappa, A. Olmo-García, Vaidehi S. Paliya, Anna Franckowiak, A. Gil de Paz, Robert Stein, Markus Böttcher, Aaron Dominguez, and 24420530 - Böttcher, Markus
Subjects: Astrofísica, 010504 meteorology & atmospheric sciences, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, 01 natural sciences, Astrophysical jet, 0103 physical sciences, Blazar, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, High Energy Astrophysical Phenomena (astro-ph.HE), Physics, Neutron Star Interior Composition Explorer, X-ray active galactic nuclei, Astronomy and Astrophysics, Redshift, Black hole, Astronomía, Neutrino astronomy, Space and Planetary Science, BL Lacertae objects, Spectral energy distribution, Relativistic jets, Neutrino, Astrophysics - High Energy Astrophysical Phenomena
Abstract: The recent spatial and temporal coincidence of the blazar TXS 0506+056 with the IceCube detected neutrino event IC-170922A has opened up a realm of multi-messenger astronomy with blazar jets as a plausible site of cosmic-ray acceleration. After TXS 0506+056, a second blazar, BZB J0955+3551, has recently been found to be spatially coincident with the IceCube detected neutrino event IC-200107A and undergoing its brightest X-ray flare measured so far. Here, we present the results of our multi-frequency campaign to study this peculiar event that includes observations with the NuSTAR, Swift, NICER, and 10.4 m Gran Telescopio Canarias (GTC). The optical spectroscopic observation from GTC secured its redshift as $z=0.55703^{+0.00033}_{-0.00021}$ and the central black hole mass as 10$^{8.90\pm0.16}~M_{\odot}$. Both NuSTAR and NICER data reveal a rapid flux variability albeit at low-significance ($\lesssim3.5\sigma$). We explore the origin of the target photon field needed for the photo-pion production using analytical calculations and considering the observed optical-to-X-ray flux level. We conclude that seed photons may originate from outside the jet, similar to that reported for TXS 0506+056, although a scenario invoking a co-moving target photon field (e.g., electron-synchrotron) can not be ruled out. The electromagnetic output from the neutrino-producing photo-hadronic processes are likely to make only a sub-dominant contribution to the observed spectral energy distribution suggesting that the X-ray flaring event may not be directly connected with IC-200107A., Comment: Accepted for publication in the Astrophysical journal
Published: 2020

5. Exploiting High-Energy Polarization in Blazars

Author: Lenté Dreyer, Markus Böttcher, 22187405 - Dreyer, Lenté, and 24420530 - Böttcher, Markus
Subjects: Physics, Astrophysics::High Energy Astrophysical Phenomena, Hadron, Monte Carlo method, Thermal, Polarimetry, Compton scattering, Spectral density, Astrophysics, Anisotropy, Blazar
Abstract: The spectral energy distributions (SEDs) and variability of astrophysical sources can be modeled in many different ways, in particular, the production of $X$-rays and $\gamma$-rays in the SEDs of blazars. High-energy polarimetry can probe the most active jet regions with the most efficient particle accelerations, and thus serve as a powerful tool to distinguish between models. We summarize the scientific potential and model predictions for high-energy polarization of blazar jets. The advantages of using Monte Carlo methods to study high-energy polarization from anisotropic Compton scattering, by thermal and non-thermal particles, will be discussed. This will reinforce the use of measurements of polarization signatures to suggest observational strategies in future projects and to use polarization as a diagnostic to distinguish between leptonic and hadronic high-energy emission from blazars.
Published: 2019
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6. An analytical hadronic synchrotron mirror model forblazars - Application to 3C279

Author: Laenita Lorraine Oberholzer, Markus Böttcher, 24420530 - Böttcher, Markus, and 24933627 - Oberholzer, Laenita L.
Subjects: Physics, Observatory, law, Astrophysics::High Energy Astrophysical Phenomena, Gamma ray, Proton Synchrotron, Quasar, High Energy Stereoscopic System, Astrophysics, Blazar, Redshift, Flare, law.invention
Abstract: On the 28th of January, the High Energy Stereoscopic System (H.E.S.S. the world’s largest ground-based gamma-ray observatory, located in Namibia) detected an orphan TeV gamma-ray flare in 3C279, not accompanied by flaring in the adjacent GeV gamma-ray regime. This is a gamma ray loud FSRQ (flat spectrum radio quasar) with a redshift of z = 0.538. Orphan flares have to be caused by different processes than normal gamma ray flares, which are typically broad-band flares, characterized by variability across the entire electromagnetic spectrum. Specifically, the hadronic mirror model has been proposed to provide a consistent explanation of this flare. The expected target photon densities have been calculated analytically using the cloud/mirror model starting from basic physical principles. This is compared to the density required to have the proton-gamma output approximately equal to the proton synchrotron radiation. The results are within one order of magnitude of each other. This is promising and shows that this model is feasible.
Published: 2019
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7. Calorimetric Neutrino Expectations from Bright Blazar Flares

Author: Markus Böttcher, Michael Kreter, Sara Buson, Matthias Kadler, Felicia Krauss, 24420530 - Böttcher, Markus, and 33379009 - Kreter, Michael
Subjects: Physics, symbols.namesake, KM3NeT, Proton, Astrophysics::High Energy Astrophysical Phenomena, symbols, Astrophysics, Neutrino, Poisson distribution, Blazar, Event (particle physics), Coincidence, Fermi Gamma-ray Space Telescope
Abstract: Blazar jets are extreme environments, in which relativistic proton interactions with an ultraviolet photon field could give rise to photopion production. High-confidence associations of individual high-energy neutrinos with blazar flares could be achieved via spatially and temporally coincident detections. In 2017, the track-like, extremely high-energy neutrino event IC 170922A was found to coincide with increased $\gamma$-ray emission from the blazar TXS 0506+056, leading to the identification of the most promising neutrino source candidate so far. We test the chance coincidence of such events by calculating the expected number of neutrinos that can be detected by IceCube, based on a broadband parametrization of bright short-term blazar flares that were observed in the past 8 years by Fermi/LAT. We find that the integrated keV-to-GeV fluence of most individual blazar flares is far too small to yield a substantial Poisson probability for the detection of one or more neutrinos with IceCube. In contrast to such short-term flares that usually last only a few days or less, TXS0506+056 did show a major outburst that lasted several months, giving rise to a much higher fluence than most short blazar flares. We show, based on the calorimetric argumentation presented in this work, that the association of the IC 170922A neutrino with TXS 0506+056 is energetically plausible at a significance level of about 3.5 $\sigma$. We further discuss strategies to search for more significant associations in future data unblindings of IceCube and KM3NeT.
Published: 2019
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8. On the Detection Potential of Blazar Flares for Current Neutrino Telescopes

Author: K. Mannheim, Felicia Krauß, Matthias Kadler, Michael Kreter, S. Buson, Markus Böttcher, Roopesh Ojha, Jörn Wilms, 33379009 - Kreter, Michael, and 24420530 - Böttcher, Markus
Subjects: 010504 meteorology & atmospheric sciences, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Library science, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, 0103 physical sciences, Aerospace, 010303 astronomy & astrophysics, Ultraviolet radiation, Data archive, 0105 earth and related environmental sciences, High Energy Astrophysical Phenomena (astro-ph.HE), Physics, Active galactic nuclei, Gamma-ray astronomy, business.industry, Astronomy and Astrophysics, Neutrino astronomy, Space and Planetary Science, Research council, High energy accelerator, Christian ministry, Astrophysics - High Energy Astrophysical Phenomena, business, Administration (government), Blazars
Abstract: The work of M. Kreter and M. Bottcher is supported by the South African Research Chairs Initiative (grant no. 64789) of the Department of Science and Innovation and the National Research Foundation of South Africa. F. Kraus was supported as an Eberly Research Fellow by the Eberly College of Science at the Pennsylvania State University. We thank J.E. Davis for the development of the slxfig module that has been used to prepare the figures in this work. This research has made use of a collection of ISIS scripts provided by the Dr. Karl Remeis-Observatory, Bamberg, Germany at http://www.sternwarte.uni-erlangen.de/isis/. The Fermi LAT Collaboration acknowledges generous ongoing support from a number of agencies and institutes that have supported both the development and the operation of the LAT as well as scientific data analysis. These include the National Aeronautics and Space Administration and the Department of Energy in the United States, the Commissariat a l’Energie Atomique and the Centre National de la Recherche Scientifique / Institut National de Physique Nucleaire et de Physique des Particules in France, the Agenzia Spaziale Italiana and the Istituto Nazionale di Fisica Nucleare in Italy, the Ministry of Education, Culture, Sports, Science and Technology (MEXT), High Energy Accelerator Research Organization (KEK) and Japan Aerospace Exploration Agency (JAXA) in Japan, and the K. A. Wallenberg Foundation, the Swedish Research Council and the Swedish National Space Board in Sweden. Additional support for science analysis during the operations phase is gratefully acknowledged from the Istituto Nazionale di Astrofisica in Italy and the Centre National d’Etudes Spatiales in France. This work performed in part under DOE Contract DE-AC02-76SF00515. We acknowledge the use of public data from the Swift data archive.
Published: 2020
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9. Systematic Physical Characterization of the γ-Ray Spectra of 2FHL Blazars

Author: Aaron Dominguez, Markus Böttcher, Jacobus P. van den Berg, Marcos Lopez-Moya, 24182869 - Van den Berg, Jacobus Petrus, and 24420530 - Böttcher, Markus
Subjects: galaxies [Gamma rays], active [Galaxies], 010504 meteorology & atmospheric sciences, Thomson scattering, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Astrophysics, Electron, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Spectral line, 0103 physical sciences, Blazar, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Physics, High Energy Astrophysical Phenomena (astro-ph.HE), non-thermal [Radiation mechanisms], Scattering, Relativistic processes, Compton scattering, Astronomy and Astrophysics, Quasar, Space and Planetary Science, jets [Galaxies], Física nuclear, Astrophysics - High Energy Astrophysical Phenomena, Fermi Gamma-ray Space Telescope
Abstract: We test different physically motivated models for the spectral shape of the $\gamma$-ray emission in a sample of 128 blazars with known redshifts detected by the Fermi Large Area Telescope (LAT) at energies above 50 GeV. The first nine years of LAT data in the energy range from 300 MeV to 2 TeV are analyzed in order to extend the spectral energy coverage of the 2FHL blazars in our sample. We compare these spectral data to four leptonic models for the production of $\gamma$-rays through Compton scattering by a population of electrons with different spectral shapes. In the first three models we consider Compton scattering in the Thomson regime with different acceleration mechanisms for the electrons. In the fourth model we consider Compton scattering by a pure power law distribution of electrons with spectral curvature due to scattering in the Klein-Nishina regime. The majority of blazar $\gamma$-ray spectra are preferentially fit with either a power law with exponential cut-off in the Thomson regime or a power law electron distribution with Compton scattering in the Klein-Nishina regime, while a log-parabola with a low-energy power-law and broken power-law spectral shape in the Thomson regime appears systematically disfavoured, which is likely a consequence of the restriction to pure Thomson scattering which we imposed on those models. This finding may be an indication that the $\gamma$-ray emission from FSRQs in the 2FHL catalog is dominated by Compton scattering of radiation from the dusty torus, while in the case of BL Lac objects, it is dominated by synchrotron self-Compton radiation., Comment: Accepted for publication in the Astrophysical Journal
Published: 2019

10. Centaurus A: Hard X-ray and soft gamma-ray lightcurve correlation

Author: Michael Backes, I. D. Davids, Markus Böttcher, 13146629 - Davids, Isak Delberth, 24420530 - Böttcher, Markus, 28644743 - Backes, Michael, and 28644743 - Backes, M.
Subjects: Physics, Supermassive black hole, Solar mass, Radio galaxy, Electromagnetic spectrum, Astrophysics::High Energy Astrophysical Phenomena, Centaurus A, Gamma ray, Flux, Astrophysics, Light curve, Astrophysics::Galaxy Astrophysics
Abstract: Centaurus A (Cen A), powered by a 55 million solar mass supermassive black hole, has been intensively monitored in all accessible wavelength ranges of the electromagnetic spectrum. However, its gamma-ray flux, both in the H.E.S.S. very-high and the Fermi-LAT high-energy gamma-ray regimes, is relatively faint, hampering lightcurve analyses. Yet, the extensive long-term light curve data from Fermi-LAT and Swift-BAT (hard X-rays) allows for cross-correlation studies. We find a hint that X-ray emission from Cen A precedes the gamma rays by 25 days. If this lag is real and related to a gamma-gamma absorption effect in the broad-line region (BLR) around the central source, then we can constrain the size of the BLR using light-travel time arguments. These are first results of extended light curve correlation studies between high-energy gamma rays and X-rays from Cen A.
Published: 2018
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11. Why the universe is unexpectedly transparent to very high energy gamma rays

Author: Markus Böttcher, Hassan Abdalla, 26598973 - Abdalla, Hassan, and 24420530 - Böttcher, Markus
Subjects: Physics, High energy, Line-of-sight, COSMIC cancer database, Opacity, Astrophysics::High Energy Astrophysical Phenomena, Gamma ray, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Lorentz covariance, Blazar
Abstract: Recent observations of distant gamma ray sources indicate that the universe may be more transparent to VHE-gamma-rays than expected. In this paper we study the reduction of the EBL gamma-gamma opacity due to the existence of underdense regions along the line of sight to VHE gamma-ray sources and the possibility of a Lorentz Invariance Violation (LIV) signature. Therefore, we study whether one or both of these effects could be suitable to explain the spectral hardening observed in a few VHE gamma-ray sources. We found that, although the cosmic opacity for VHE gamma rays with energy more than 10 TeV can be strongly reduced, the spectral hardening feature observed in some VHE gamma-ray blazars with energy from 300 GeV up to few TeVs (e.g. PKS 1424+240) still remains puzzling.
Published: 2018
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12. VHE γ-ray discovery and multi-wavelength study of the blazar 1ES 2322-409

Author: M. Zacharias, Marek Jamrozy, Jim Hinton, A. Schulz, R. Tuffs, R. Simoni, Dmitry Khangulyan, D. A. Sanchez, Helene Sol, H. Ndiyavala, S. Bernhard, J. Devin, M. Böttcher, F. Ait Benkhali, S. Eschbach, C. Stegmann, Nu. Komin, M. Holler, B. van Soelen, Gerd Puehlhofer, F. Jankowsky, J. Veh, D. J. van der Walt, M. Fuessling, M. Lemoine-Goumard, M.A. Kastendieck, S. Bonnefoy, Axel Donath, A. W. Chen, I. Shilon, T. Tavernier, G. Emery, Matteo Cerruti, Michael Punch, M. Spir-Jacob, Manami Sasaki, S. Schwemmer, Andrea Santangelo, J. Lau, B. Peyaud, E. Leser, G. Hermann, Regis Terrier, Carlo Romoli, F. Gaté, R. Rauth, Fabian Schüssler, A. Jacholkowska, M. de Naurois, A. Woernlein, P. Bordas, D. A. Prokhorov, R. Marx, Werner Hofmann, Felix Spanier, Catherine Boisson, Stefan Funk, R. Zanin, R. C. G. Chaves, E. O. Angüner, D. Tiziani, I. Lypova, Stefan Wagner, Yasunobu Uchiyama, Christo Venter, D. Berge, D. Huber, D. Gottschall, P. T. O'Brien, Ullrich Schwanke, C. Perennes, Ruizhi Yang, S. Gabici, C. van Rensburg, J.F. Glicenstein, A. Marcowith, C. Hoischen, Wlodek Kluzniak, S. Saito, G. Fontaine, A. Zech, G. Maurin, K. Kosack, Jacek Niemiec, M. Lorentz, J. Becker Tjus, P.-O. Petrucci, L. Mohrmann, R. Steenkamp, A. Djannati-Ataï, S. Nakashima, Robert Wagner, J. Lefaucheur, A. Wierzcholska, Atreyee Sinha, C. van Eldik, C. Mariaud, A.M. Taylor, Aion Viana, S. Klepser, Olaf Reimer, R. J. White, G. Martí-Devesa, J.-P. Lenain, N. Shafi, Pierre Brun, T. Takahashi, Michael Backes, Gianluca Giavitto, T. Garrigoux, R. Blackwell, J. Hahn, N. Zywucka, Dieter Horns, I.D. Davids, S. Raab, Thomas Murach, E. Ruiz-Velasco, K. Egberts, Tim Holch, Reinhard Schlickeiser, M. Tsirou, G. Henri, A. M. W. Mitche, M. Mohamed, G. Vasileiadis, M. Ostrowski, H. Odaka, S. Chandra, P.J. Meintjes, S. Fegan, Marco Padovani, T. Lohse, A. Reimer, J. Bregeon, M. Renaud, H. Iwasaki, A. Carosi, R. R. Kruger, A. Lemière, H. Abdalla, B. Khélifi, Denys Malyshev, Nachiketa Chakraborty, K. Bernloehr, Stefan Ohm, S. Caroff, S. Pita, E. Moulin, Tomasz Bulik, D. Glawion, M. Panter, T. Bylund, Mohanraj Senniappan, A. Fiasson, L. Dirson, V. Poireau, L. Oakes, I. Sushch, A.A. Zdziarski, I. Jung-Richardt, Yvonne Becherini, D. Kerszberg, Masanori Arakawa, I. Oya, G. Heinzelmann, Felix Aharonian, L. Tibaldo, Zorawar Wadiasingh, B. Condon, Monica Barnard, F. Zefi, M. Buechele, M. Capasso, S. Krakau, V. Sahakian, D. Jankowsky, Q. Piel, J. Zorn, U. Katz, A.S. Seyffert, J.-P. Tavernet, P. Vincent, G. Lamanna, T. Vuillaume, P. deWilt, M. Seglar-Arroyo, J. King, B. Rudak, A. Priyana Noel, A. Dmytriiev, R. Moderski, V. Marandon, K. Katarzyński, L. Rinchiuso, L. Jouvin, M. Katsuragawa, C. Arcaro, M. Kraus, A. Specovius, Francois Brun, M. Tluczykont, Celine Armand, C. Steppa, M. Arrieta, Heike Prokoph, M. Haupt, Lukasz Stawarz, J. Dyks, K. Shiningayamwe, Andreas Quirrenbach, N. Tsuji, C. Trichard, J.-P. Ernenwein, R. D. Parsons, A. Ziegler, L. O. 'C. Drury, Ruben Lopez-Coto, M.-H. Grondin, P. Wagner, C. Dei, Y.A. Gallant, Gavin Rowell, M. Bryan, D. Zaborov, F. Niederwanger, Jacco Vink, Sabrina Casanova, H. J. Voelk, Frank M. Rieger, F. Voisin, J. Bolmont, S. Colafrancesco, 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), Laboratoire d'Annecy de Physique des Particules (LAPP/Laboratoire d'Annecy-le-Vieux de Physique des Particules), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Laboratoire Univers et Théories (LUTH (UMR_8102)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique Nucléaire et de Hautes Énergies (LPNHE (UMR_7585)), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Univers et Particules de Montpellier (LUPM), Université de Montpellier (UM)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Centre d'Etudes Nucléaires de Bordeaux Gradignan (CENBG), Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, AstroParticule et Cosmologie (APC (UMR_7164)), 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), Laboratoire Leprince-Ringuet (LLR), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Collège de France (CdF), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Centre National d'Études Spatiales [Toulouse] (CNES)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), Département d'Astrophysique (ex SAP) (DAP), 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, Laboratoire d'Electronique et des Technologies de l'Information (CEA-LETI), Université Grenoble Alpes (UGA)-Direction de Recherche Technologique (CEA) (DRT (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), H.E.S.S., H.E.S.S. Collaboration, 26598973 - Abdalla, Hassan, 30588766 - Arcaro, Cornelia, 28644743 - Backes, Michael, 20574266 - Barnard, Monica, 24420530 - Böttcher, Markus, 31125417 - Chandra, Sunil, 26909995 - Garrigoux, Tania, 11749903 - Krüger, Petrus Paulus, 26403366 - Ndiyavala, Hambeleleni, 20126999 - Seyffert, Albertus Stefanus, 25161814 - Spanier, Felix Alexander, 24922986 - Sushch, Iurii, 10060499 - Van der Walt, Diederick Johannes, 21106266 - Van Rensburg, Carlo, 12006653 - Venter, Christo, 26594080 - Wadiasingh, Zorawar, 29092086 - Zacharias, Michael, Aix Marseille Université (AMU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Annecy de Physique des Particules (LAPP), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Université Montpellier 2 - Sciences et Techniques (UM2)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Montpellier (UM)-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)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Collège de France (CdF (institution)), Centre National d'Études Spatiales [Toulouse] (CNES)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA), Commissariat à l'énergie atomique et aux énergies alternatives - Laboratoire d'Electronique et de Technologie de l'Information (CEA-LETI), Direction de Recherche Technologique (CEA) (DRT (CEA)), Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Montpellier 2 - Sciences et Techniques (UM2), 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 National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), 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), Faculty of Science, and High Energy Astrophys. & Astropart. Phys (API, FNWI)
Subjects: gamma-rays: galaxies, principal component analysis, Energy flux, Astrophysics, 01 natural sciences, pixel, HESS, ultraviolet, optical, energy: flux, HESS - Abteilung Hofmann, photon: flux, 010303 astronomy & astrophysics, model: leptonic, Physics, radio wave, density, active, [Galaxies], Gamma ray, galaxies [Gamma-rays], individual: 1ES 2322-409 [BL Lacertae objects], active [galaxies], infrared, Spectral energy distribution, Astrophysics - High Energy Astrophysical Phenomena, Astrophysics::High Energy Astrophysical Phenomena, galaxies: active, Astrophysics::Cosmology and Extragalactic Astrophysics, gamma ray: energy spectrum, GLAST, blazar, X-ray, 0103 physical sciences, Blazar, Astroparticle physics, non-thermal [Radiation mechanisms], synchrotron radiation, background, 010308 nuclear & particles physics, Institut für Physik und Astronomie, Astronomy and Astrophysics, radiation mechanisms: non-thermal, redshift, proton synchrotron, MAGIC, Redshift, Crab Nebula, gamma ray: VHE, Space and Planetary Science, spectral, ddc:520, High Energy Physics::Experiment, BL Lacertae objects: individual: 1ES 2322−409, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Fermi Gamma-ray Space Telescope
Abstract: 著者人数: H.E.S.S. Collaboration 233名 (所属. 宇宙航空研究開発機構宇宙科学研究所(JAXA)(ISAS): 桂川, 美穂; 中島, 真也; 小高, 裕和; 高橋, 忠幸), Number of authors: H.E.S.S. Collaboration 233 (Affiliation. Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency(JAXA)(ISAS): Katsuragawa, Miho; Nakashima, Shinya; Odaka, Hirokazu; Takahashi, Tadayuki), Accepted: 2018-09-29, 資料番号: SA1180422000
Published: 2018
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13. Pressure Balance and Intrabinary Shock Stability in Rotation-Powered State Redback and Transitional Millisecond Pulsar Binary Systems

Author: Christo Venter, Markus Böttcher, Alice K. Harding, Zorawar Wadiasingh, Patrick Kilian, 24420530 - Böttcher, Markus, 12006653 - Venter, Christo, 26594080 - Wadiasingh, Zorawar, and 28233530 - Kilian, Patrick
Subjects: Shock wave, Angular momentum, Accretion, Astrophysics::High Energy Astrophysical Phenomena, general [Pulsars], Magnetosphere, FOS: Physical sciences, Astrophysics, 01 natural sciences, Shock waves, Pulsar, Millisecond pulsar, 0103 physical sciences, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Physics, High Energy Astrophysical Phenomena (astro-ph.HE), mass-loss [Stars], 010308 nuclear & particles physics, Astronomy and Astrophysics, Observable, Accretion (astrophysics), magnetic field [Stars], Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Stellar mass loss, Accretion disks, binaries [X-rays], Astrophysics - High Energy Astrophysical Phenomena
Abstract: A number of low-mass millisecond pulsar (MSP) binaries in their rotation-powered state exhibit double-peaked X-ray orbital modulation centered at inferior pulsar conjunction. This state, which has been known to persist for years, has recently been interpreted as emission from a shock that enshrouds the pulsar. However, the pressure balance for such a configuration is a crucial unresolved issue. We consider two scenarios for pressure balance: a companion magnetosphere and stellar mass loss with gas dominance. It is found that the magnetospheric scenario requires several kilogauss poloidal fields for isobaric surfaces to enshroud the MSP as well as for the magnetosphere to remain stable if there is significant mass loss. For the gas-dominated scenario, it is necessary that the companion wind loses angular momentum prolifically as an advection or heating-dominated flow. Thermal bremsstrahlung cooling in the flow may be observable as a UV to soft X-ray component independent of orbital phase if the mass rate is high. We formulate the general requirements for shock stability against gravitational influences in the pulsar rotation-powered state for the gas-dominated scenario. We explore stabilizing mechanisms, principally irradiation feedback, which anticipates correlated shock emission and companion variability and predicts $ F_\gamma/F_{\rm X} \lesssim 14$ for the ratio of pulsar magnetospheric $\gamma$-ray to total shock soft-to-hard X-ray fluxes. This stability criterion implies an unbroken extension of X-ray power-law emission to hundreds of keV for some systems. We explore observational discriminants between the gas-dominated and magnetospheric scenarios, motivating contemporaneous radio through $\gamma$-ray monitoring of these systems., Comment: Accepted to ApJ; 31 pages, 9 figures; comments welcome
Published: 2018
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14. Multi-wavelength observations of flaring blazars with ATOM and Fermi-LAT

Author: Omar M. Kurtanidze, Felix Jankowsky, Jean-Philippe Lenain, Markus Böttcher, S. J. Wagner, Alicja Wierzcholska, Michael Zacharias, 29092086 - Zacharias, Michael, and 24420530 - Böttcher, Markus
Subjects: Physics, Astrophysics::High Energy Astrophysical Phenomena, Astrophysics::Instrumentation and Methods for Astrophysics, Multi wavelength, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Optical telescope, law.invention, CTA-102, Telescope, law, Atom, Blazar, Fermi Gamma-ray Space Telescope
Abstract: The Automatic Telescope for Optical Monitoring is a 75cm optical telescope located at the H.E.S.S. site in Namibia. Since 2005, it monitors around 250 gamma-ray emitting AGN and has observed numerous blazar flares in several colour bands with multiple measurements during any given night. We present recent flaring events of two FSRQ – 3C 279 and CTA 102 – together with corresponding multi-wavelength data including Fermi-LAT, and examine possible correlations between energy bands.
Published: 2017
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15. The Long-Lasting Activity in the Flat Spectrum Radio Quasar (FSRQ) CTA 102

Author: Felix Jankowsky, Jean-Philippe Lenain, Michael Zacharias, Markus Böttcher, Alicja Wierzcholska, Stefan Wagner, Laboratoire de Physique Nucléaire et de Hautes Énergies (LPNHE (UMR_7585)), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), 24420530 - Böttcher, Markus, and 29092086 - Zacharias, Michael
Subjects: Long lasting, Active galactic nucleus, lcsh:Astronomy, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Multi wavelength, Astrophysics, blazar variability, 01 natural sciences, blazar modeling, lcsh:QB1-991, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, Blazar modeling, 10. No inequality, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, High Energy Astrophysical Phenomena (astro-ph.HE), Physics, Active galactic nuclei, Multi-wavelength, Jet (fluid), 010308 nuclear & particles physics, Active Galactic Nuclei, Astronomy and Astrophysics, Observable, Quasar, Light curve, Astrophysics - Astrophysics of Galaxies, CTA-102, Multi-Wavelength, 13. Climate action, Astrophysics of Galaxies (astro-ph.GA), Blazar variability, Astrophysics - High Energy Astrophysical Phenomena, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract: The flat spectrum radio quasar CTA 102 ($z = 1.032$) went through a tremendous phase of variability. Since early 2016 the gamma-ray flux level has been significantly higher than in previous years. It was topped by a four month long giant outburst, where peak fluxes were more than 100 times higher than the quiescence level. Similar trends are observable in optical and X-ray energies. We have explained the giant outburst as the ablation of a gas cloud by the relativistic jet that injects additional matter into the jet and can self-consistently explain the long-term light curve. Here, we argue that the cloud responsible for the giant outburst is part of a larger system that collides with the jet and is responsible for the years-long activity in CTA 102., 9 pages, 5 figures, accepted by Galaxies as part of the special issue "Monitoring the non-thermal Universe", a conference held in Cochem, Germany, 17th - 21st September 2018
Published: 2019
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16. PANGU (PAir-productioN Gamma-ray Unit): A High Resolution Gamma-ray Space Telescope

Author: Meng Su, Mario Nicola Mazziottai, Jin Chang, Xin Wu, Mark Pearce, Christian Farnier, A. Morselli, Peter von Ballmoos, Isabelle Grenier, Markus Böttcher, F. Gargano, Giovanni Ambrosi, Yi-Zhong Fan, Martin Pohl, Andrzej A. Zdziarski, R. Walter, Masha Chernyakova, Wojtek Hajdas, and 24420530 - Böttcher, Markus
Subjects: Physics, Optics, Pair production, Spitzer Space Telescope, business.industry, Resolution (electron density), Gamma ray, business
Published: 2016
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17. First ground-based measurement of sub-20 GeV to 100 GeV γ-Rays from the Vela pulsar with H.E.S.S. II

Author: Collaboration, H. E. S. S., Abdalla, H., Aharonian, F., Benkhali, F. Ait, Angüner, E. O., Arakawa, M., Arcaro, C., Arm, C., Arrieta, M., Backes, M., Barnard, M., Becherini, Y., Tjus, J. Becker, Berge, D., Bernhard, S., Bernlöhr, K., Blackwell, R., Böttcher, M., Boisson, C., Bolmont, J., Bonnefoy, S., Bordas, P., Bregeon, J., Brun, F., Brun, P., Bryan, M., Büchele, M., Bulik, T., Bylund, T., Capasso, M., Caroff, S., Carosi, A., Casanova, S., Cerruti, M., Chakraborty, N., Ch, S., Chaves, R. C. G., Chen, A., Colafrancesco, S., Condon, B., Davids, I. D., Deil, C., Devin, J., deWilt, P., Dirson, L., Djannati-Ataï, A., Dmytriiev, A., Donath, A., Doroshenko, V., Drury, L. O'C., Dyks, J., Egberts, K., Emery, G., Ernenwein, J. -P., Eschbach, S., Fegan, S., Fiasson, A., Fontaine, G., Funk, S., Füßling, M., Gabici, S., Gallant, Y. A., Gaté, F., Giavitto, G., Glawion, D., Glicenstein, J. F., Gottschall, D., Grondin, M. -H., Hahn, J., Haupt, M., Heinzelmann, G., Henri, G., Hermann, G., Hinton, J. A., Hofmann, W., Hoischen, C., Holch, T. L., Holler, M., Horns, D., Huber, D., Iwasaki, H., Jacholkowska, A., Jamrozy, M., Jankowsky, D., Jankowsky, F., Jouvin, L., Jung-Richardt, I., Kastendieck, M. A., Katarzyński, K., Katsuragawa, M., Katz, U., Kerszberg, D., Khangulyan, D., Khélifi, B., King, J., Klepser, S., Kluźniak, W., Komin, Nu., Kosack, K., Krakau, S., Kraus, M., Krüger, P. P., Lamanna, G., Lau, J., Lefaucheur, J., Lemière, A., Lemoine-Goumard, M., Lenain, J. -P., Leser, E., Lohse, T., Lorentz, M., López-Coto, R., Lypova, I., Malyshev, D., Mar, V., Marcowith, A., Mariaud, C., Martí-Devesa, G., Marx, R., Maurin, G., Meintjes, P. J., Mitchell, A. M. W., Moderski, R., Mohamed, M., Mohrmann, L., Moulin, E., Murach, T., Nakashima, S., de Naurois, M., Ndiyavala, H., Niederwanger, F., Niemiec, J., Oakes, L., O'Brien, P., Odaka, H., Ohm, S., Ostrowski, M., Oya, I., Padovani, M., Panter, M., Parsons, R. D., Perennes, C., Petrucci, P. -O., 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., Reimer, A., Reimer, O., Renaud, M., Rieger, F., Rinchiuso, L., Romoli, C., Rowell, G., Rudak, B., Ruiz-Velasco, E., Sahakian, V., Saito, S., Sanchez, D. A., Santangelo, A., Sasaki, M., Schlickeiser, R., Schüssler, F., Schulz, A., Schwanke, U., Schwemmer, S., Seglar-Arroyo, M., Senniappan, M., Seyffert, A. S., Shafi, N., Shilon, I., Shiningayamwe, K., Simoni, R., Sinha, A., Sol, H., Spanier, F., Specovius, A., Spir-Jacob, M., Stawarz, Ł., Steenkamp, R., Stegmann, C., Steppa, C., Takahashi, T., Tavernet, J. -P., Tavernier, T., Taylor, A. M., Terrier, R., Tibaldo, L., Tiziani, D., Tluczykont, M., Trichard, C., Tsirou, M., Tsuji, N., 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., Voisin, F., Völk, H. J., Vuillaume, T., Wadiasingh, Z., Wagner, S. J., Wagner, R. M., White, R., Wierzcholska, A., Yang, R., Zaborov, D., Zacharias, M., Zanin, R., Zdziarski, A. A., Zech, A., Zefi, F., Ziegler, A., Zorn, J., Żywucka, N., Kerr, M., Johnston, S., Shannon, R. M., Centre de Physique des Particules de Marseille (CPPM), Aix Marseille Université (AMU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Annecy de Physique des Particules (LAPP), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Laboratoire Univers et Théories (LUTH (UMR_8102)), Institut national des sciences de l'Univers (INSU - CNRS)-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), Laboratoire de Physique Nucléaire et de Hautes Énergies (LPNHE (UMR_7585)), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Univers et Particules de Montpellier (LUPM), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Centre d'Etudes Nucléaires de Bordeaux Gradignan (CENBG), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Astrophysique Interprétation Modélisation (AIM (UMR7158 / UMR_E_9005 / UM_112)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Leprince-Ringuet (LLR), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique Théorique de l'ENS [École Normale Supérieure] (LPTENS), Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), AstroParticule et Cosmologie (APC (UMR_7164)), 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)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, HESS, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Montpellier 2 - Sciences et Techniques (UM2), Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7), Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Laboratoire de Physique Théorique de l'ENS (LPTENS), Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Centre National d'Études Spatiales [Toulouse] (CNES)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Aix Marseille Université (AMU), Laboratoire d'Annecy de Physique des Particules (LAPP/Laboratoire d'Annecy-le-Vieux de Physique des Particules), Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), PSL Research University (PSL)-PSL Research University (PSL)-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 Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Université de Montpellier (UM)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), 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), Centre National d'Études Spatiales [Toulouse] (CNES)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), Faculty of Science, High Energy Astrophys. & Astropart. Phys (API, FNWI), Gravitation and Astroparticle Physics Amsterdam, Université Montpellier 2 - Sciences et Techniques (UM2)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS), 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), 12006653 - Venter, Christo, 26594080 - Wadiasingh, Zorawar, 29092086 - Zacharias, Michael, 21106266 - Van Rensburg, Carlo, 10060499 - Van der Walt, Diederick Johannes, 25161814 - Spanier, Felix Alexander, 20126999 - Seyffert, Albertus Stefanus, 26403366 - Ndiyavala, Hambeleleni, 11749903 - Krüger, Petrus Paulus, 31125417 - Chandra, Sunil, 24420530 - Böttcher, Markus, 30588766 - Arcaro, Cornelia, 26598973 - Abdalla, Hassan, and 20574266 - Barnard, Monica
Subjects: Photon, Astrophysics::High Energy Astrophysical Phenomena, Astrophysics, gamma rays: stars, Vela, 01 natural sciences, Upper and lower bounds, GLAST, law.invention, Telescope, Pulsar, law, HESS, 0103 physical sciences, threshold, overlap, Cutoff, 010303 astronomy & astrophysics, pulsar, Physics, individual: PSR B0833-45 [Pulsars], non-thermal [Radiation mechanisms], 010308 nuclear & particles physics, photon, stars [Gamma rays], Gamma ray, Institut für Physik und Astronomie, Astronomy and Astrophysics, radiation mechanisms: non-thermal, Light curve, pulsed, pulsars: individual: PSR B0833-45, gamma ray, Space and Planetary Science, curvature, ddc:520, Astrophysics - High Energy Astrophysical Phenomena, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract: Astronomy and astrophysics 620, A66 (2018). doi:10.1051/0004-6361/201732153, We report on the measurement and investigation of pulsed high-energy γ-ray emission from the Vela pulsar, PSR B0833−45, based on observations with the largest telescope of H.E.S.S., CT5, in monoscopic mode, and on data obtained with the Fermi-LAT.Methods. Data from 40.3 h of observations carried out with the H.E.S.S. II array from 2013 to 2015 have been used. A dedicated very low-threshold event reconstruction and analysis pipeline was developed to achieve the lowest possible energy threshold. Eight years of Fermi-LAT data were analysed and also used as reference to validate the CT5 telescope response model and analysis methods.Results. A pulsed γ-ray signal at a significance level of more than 15σ is detected from the P2 peak of the Vela pulsar light curve. Of a total of 15 835 events, more than 6000 lie at an energy below 20 GeV, implying a significant overlap between H.E.S.S. II-CT5 and the Fermi-LAT. While the investigation of the pulsar light curve with the LAT confirms characteristics previously known up to 20 GeV in the tens of GeV energy range, CT5 data show a change in the pulse morphology of P2, i.e. an extreme sharpening of its trailing edge, together with the possible onset of a new component at 3.4σ significance level. Assuming a power-law model for the P2 spectrum, an excellent agreement is found for the photon indices (Γ ≃ 4.1) obtained with the two telescopes above 10 GeV and an upper bound of 8% is derived on the relative offset between their energy scales. Using data from both instruments, it is shown however that the spectrum of P2 in the 10–100 GeV has a pronounced curvature; this is a confirmation of the sub-exponential cut-off form found at lower energies with the LAT. This is further supported by weak evidence of an emission above 100 GeV obtained with CT5. In contrast, converging indications are found from both CT5 and LAT data for the emergence of a hard component above 50 GeV in the leading wing (LW2) of P2, which possibly extends beyond 100 GeV.Conclusions. The detection demonstrates the performance and understanding of CT5 from 100 GeV down to the sub-20 GeV domain, i.e. unprecedented low energy for ground-based γ-ray astronomy. The extreme sharpening of the trailing edge of the P2 peak found in the H.E.S.S. II light curve of the Vela pulsar and the possible extension beyond 100 GeV of at least one of its features, LW2, provide further constraints to models of γ-Ray emission from pulsars., Published by EDP Sciences, Les Ulis
Published: 2018
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18. Studies of Relativistic Jets in Active Galactic Nuclei with SKA

Author: Marcello Giroletti, José L. Gómez, Leonid Gurvits, Matthew L. Lister, Shane O'Sullivan, Manuel Perucho, Markos Georganopoulos, John F. C. Wardle, Z. Paragi, G. Ghisellini, Lukasz Stawarz, R. Laing, Markus Böttcher, Eileen T. Meyer, Heino Falcke, Yosuke Mizuno, José-María Martí, Paolo Padovani, I. Agudo, Dominik R. G. Schleicher, Gabriele Giovannini, Nektarios Vlahakis, and 24420530 - Böttcher, Markus
Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO), Active galactic nucleus, 010504 meteorology & atmospheric sciences, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, Jet (particle physics), 01 natural sciences, Astrophysical jet, 0103 physical sciences, Very-long-baseline interferometry, Instrumentation and Methods for Astrophysics (astro-ph.IM), 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences, High Energy Astrophysical Phenomena (astro-ph.HE), Physics, Star formation, Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy, Astrophysics - Astrophysics of Galaxies, Galaxy, Characterization (materials science), 13. Climate action, Astrophysics of Galaxies (astro-ph.GA), Brightness temperature, Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Instrumentation and Methods for Astrophysics, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract: Relativistic jets in active galactic nuclei (AGN) are among the most powerful astrophysical objects discovered to date. Indeed, jetted AGN studies have been considered a prominent science case for SKA, and were included in several different chapters of the previous SKA Science Book (Carilli & Rawlings 2004). Most of the fundamental questions about the physics of relativistic jets still remain unanswered, and await high-sensitivity radio instruments such as SKA to solve them. These questions will be addressed specially through analysis of the massive data sets arising from the deep, all-sky surveys (both total and polarimetric flux) from SKA1. Wide-field very-long-baseline-interferometric survey observations involving SKA1 will serve as a unique tool for distinguishing between extragalactic relativistic jets and star forming galaxies via brightness temperature measurements. Subsequent SKA1 studies of relativistic jets at different resolutions will allow for unprecedented cosmological studies of AGN jets up to the epoch of re-ionization, enabling detailed characterization of the jet composition, magnetic field, particle populations, and plasma properties on all scales. SKA will enable us to study the dependence of jet power and star formation on other properties of the AGN system. SKA1 will enable such studies for large samples of jets, while VLBI observations involving SKA1 will provide the sensitivity for pc-scale imaging, and SKA2 (with its extraordinary sensitivity and dynamic range) will allow us for the first time to resolve and model the weakest radio structures in the most powerful radio-loud AGN., 19 pages, 4 figures; to appear as part of 'Cosmic Magnetism' in Proceedings 'Advancing Astrophysics with the SKA (AASKA14)', PoS(AASKA14_093)
Published: 2015
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19. The high-energy γ-ray emission of AP Librae

Author: H.E.S.S.Collaboration, Abramowski, A., Aharonian, F., Ait Benkhali, F., Akhperjanian, A.G., Angüner, E., Anton, G., Backes, M., Balenderan, S., Balzer, A., Barnacka, A., Becherini, Y., Becker Tjus, J., Bernlöhr, K., Birsin, E., Bissaldi, E., Biteau, J., Böttcher, M., Boisson, C., Bolmont, J., Bordas, P., Brucker, J., Brun, F., Brun, P., Bulik, T., Carrigan, S., Casanova, S., Chadwick, P.M., Chalme-Calvet, R., Chaves, R.C.G., Cheesebrough, A., Chrétien, M., Colafrancesco, S., Cologna, G., Conrad, J., Couturier, C., Cui, Y., Dalton, M., Daniel, M.K., Davids, I.D., Degrange, B., Deil, C., deWilt, P., Dickinson, H.J., Djannati-Ataï, A., Domainko, W., Drury, L.O'C., Dubus, G., Dutson, K., Dyks, J., Dyrda, M., Edwards, T., Egberts, K., Eger, P., Espigat, P., Farnier, C., Fegan, S., Feinstein, F., Fernandes, M.V., Fernandez, D., Fiasson, A., Fontaine, G., Förster, A., Füßling, M., Gajdus, M., Gallant, Y.A., Garrigoux, T., Giavitto, G., Giebels, B., Glicenstein, J.F., Grondin, M.-H., Grudzińska, M., Häffner, S., Hahn, J., Harris, J., Heinzelmann, G., Henri, G., Hermann, G., Hervet, O., Hillert, A., Hinton, J.A., Hofmann, W., Hofverberg, P., Holler, M., Horns, D., Jacholkowska, A., Jahn, C., Jamrozy, M., Janiak, M., Jankowsky, F., Jung, I., Kastendieck, M.A., Katarzyński, K., Katz, U., Kaufmann, S., Khélifi, B., Kieffer, M., Klepser, S., Klochkov, D., Kluźniak, W., Kneiske, T., Kolitzus, D., Komin, Nu., Kosack, K., Krakau, S., Krayzel, F., Krüger, P.P., Laffon, H., Lamanna, G., Lefaucheur, J., Lemière, A., Lemoine-Goumard, M., Lenain, J.-P., Lohse, T., Lopatin, A., Lu, C.-C., Marandon, V., Marcowith, A., Marx, R., Maurin, G., Maxted, N., Mayer, M., McComb, T.J.L., Méhault, J., Meintjes, P.J., Menzler, U., Meyer, M., Moderski, R., Mohamed, M., Moulin, E., Murach, T., Naumann, C.L., Naurois, M. de, Niemiec, J., Nolan, S.J., Oakes, L., Odaka, H., Ohm, S., Oña Wilhelmi, E. de, Opitz, B., Ostrowski, M., Oya, I., Panter, M., Parsons, R.D., Paz Arribas, M., Pekeur, N.W., Pelletier, G., Perez, J., Petrucci, P.-O., Peyaud, B., Pita, S., Poon, H., Pühlhofer, G., Punch, M., Quirrenbach, A., Raab, S., Raue, M., Reichardt, I., Reimer, A., Reimer, O., Renaud, M., Reyes, R. de los, Rieger, F., Rob, L., Romoli, C., Rosier-Lees, S., Rowell, G., Rudak, B., Rulten, C.B., Sahakian, V., Sanchez, D.A., Santangelo, A., Schlickeiser, R., Schüssler, F., Schulz, A., Schwanke, U., Schwarzburg, S., Schwemmer, S., Sol, H., Spengler, G., Spies, F., Stawarz, Ł., Steenkamp, R., Stegmann, C., Stinzing, F., Stycz, K., Sushch, I., Tavernet, J.-P., Tavernier, T., Taylor, A.M., Terrier, R., Tluczykont, M., Trichard, C., Valerius, K., van Eldik, C., van Soelen, B., Vasileiadis, G., Venter, C., Viana, A., Vincent, P., Völk, H.J., Volpe, F., Vorster, M., Vuillaume, T., Wagner, S.J., Wagner, P., Wagner, R.M., Ward, M., Weidinger, M., Weitze, Q., White, R., Wierzcholska, A., Willmann, P., Wörnlein, A., Wouters, D., Yang, R., Zabalza, V., Zacharias, M., Zdziarski, A.A., Zech, A., Zechlin, H.-S., Finke, J., Fortin, P., Horan, D., 24420530 - Böttcher, Markus, 23909196 - Casanova, Sabrina, 13146629 - Davids, Isak Delberth, 11749903 - Krüger, Petrus Paulus, 22050574 - Pekeur, Nicolette Whilna, 24922986 - Sushch, Iurii, 12006653 - Venter, Christo, and 12792322 - Vorster, Michael Johannes
Subjects: Physics, Spectral index, Range (particle radiation), galaxies. [Gamma rays], active [Galaxies], 010308 nuclear & particles physics, Astrophysics::High Energy Astrophysical Phenomena, Gamma ray, Astronomy and Astrophysics, Astrophysics, Type (model theory), Light curve, 7. Clean energy, 01 natural sciences, Space and Planetary Science, 0103 physical sciences, galaxies [gamma rays], individual: AP Librae [BL Lacertae objects], Spectral energy distribution, High Energy Physics::Experiment, 010303 astronomy & astrophysics, Energy (signal processing), Fermi Gamma-ray Space Telescope
Abstract: The $\gamma$-ray spectrum of the low-frequency-peaked BL Lac (LBL) object AP Librae is studied, following the discovery of very-high-energy (VHE; $E>100\,{\rm GeV}$) $\gamma$-ray emission up to the TeV range by the H.E.S.S. experiment. This makes AP Librae one of the few VHE emitters of the LBL type. The measured spectrum yields a flux of $(8.8 \pm 1.5_{\rm stat} \pm 1.8_{\rm sys}) \times 10^{-12}\ {\rm cm}^{-2} {\rm s}^{-1}$ above 130 GeV and a spectral index of $\Gamma = 2.65\pm0.19_{\rm stat}\pm0.20_{\rm sys}$. This study also makes use of \textit{Fermi}-LAT, observations in the high energy (HE, E$>$100 MeV) range, providing the longest continuous light curve (5 years) ever published on this source. The source underwent a flaring event between MJD 56306-56376 in the HE range, with a flux increase of a factor 3.5 in the 14-day bin light curve and no significant variation in spectral shape with respect to the low-flux state. While the H.E.S.S., and (low state) \textit{Fermi}-LAT fluxes are in good agreement where they overlap, a spectral curvature between the steep VHE spectrum and the \textit{Fermi}-LAT, spectrum is observed. The maximum of the $\gamma$-ray emission in the spectral energy distribution is located below the GeV energy range.
Published: 2015

20. Nature of Intra-night Optical Variability of BL Lacertae

Author: A. Rajasingam, Paul J. Wiita, Evgeni Semkov, Boyko Mihov, L. Slavcheva-Mihova, Stoyanka Peneva, Alok C. Gupta, Minfeng Gu, Rumen Bachev, Markus Böttcher, Haritma Gaur, A. Strigachev, N. Palma, Hengxiao Guo, J. A. de Diego, Ravi Joshi, and 24420530 - Böttcher, Markus
Subjects: Physics, High Energy Astrophysical Phenomena (astro-ph.HE), jets [galaxies], Flux, Astronomy, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Light curve, Wavelength, Amplitude, Space and Planetary Science, active [galaxies], photometry [galaxies], Astrophysics - High Energy Astrophysical Phenomena, Sampling interval, individual: BL Lacertae [BL Lacertae objects], BL Lac object, Visible spectrum, Linear trend
Abstract: We present the results of extensive multi-band intra-night optical monitoring of BL Lacertae during 2010--2012. BL Lacertae was very active in this period and showed intense variability in almost all wavelengths. We extensively observed it for a total for 38 nights; on 26 of them observations were done quasi-simultaneously in B, V, R and I bands (totaling 113 light curves), with an average sampling interval of around 8 minutes. BL Lacertae showed significant variations on hour-like timescales in a total of 19 nights in different optical bands. We did not find any evidence for periodicities or characteristic variability time-scales in the light curves. The intranight variability amplitude is generally greater at higher frequencies and decreases as the source flux increases. We found spectral variations in BL Lacertae in the sense that the optical spectrum becomes flatter as the flux increases but in several flaring states deviates from the linear trend suggesting different jet components contributing to the emission at different times., Comment: 12 Pages, 5 figures, 3 Tables, Accepted for Publication in MNRAS
Published: 2015
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21. Cloud Ablation by a Relativistic Jet and the Extended Flare in CTA 102 in 2016 and 2017

Author: Felix Jankowsky, Alicja Wierzcholska, Markus Böttcher, J.-P. Lenain, Stefan Wagner, Michael Zacharias, Laboratoire de Physique Nucléaire et de Hautes Énergies (LPNHE (UMR_7585)), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique Nucléaire et de Hautes Énergies ( LPNHE ), Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut National de Physique Nucléaire et de Physique des Particules du CNRS ( IN2P3 ) -Université Paris Diderot - Paris 7 ( UPD7 ) -Centre National de la Recherche Scientifique ( CNRS ), 24420530 - Böttcher, Markus, and 29092086 - Zacharias, Michael
Subjects: active [Galaxies], Particle number, [ PHYS.ASTR ] Physics [physics]/Astrophysics [astro-ph], Astrophysics::High Energy Astrophysical Phenomena, medicine.medical_treatment, galaxies: active, FOS: Physical sciences, Flux, Astrophysics, 01 natural sciences, law.invention, law, 0103 physical sciences, medicine, quasars: individual, 010303 astronomy & astrophysics, relativistic processes, High Energy Astrophysical Phenomena (astro-ph.HE), Physics, Jet (fluid), non-thermal [Radiation mechanisms], 010308 nuclear & particles physics, Relativistic processes, individual (CTA 102) [Quasars], Astronomy and Astrophysics, Quasar, radiation mechanisms: non-thermal, Ablation, Astrophysics - Astrophysics of Galaxies, CTA-102, 13. Climate action, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), Astrophysics - High Energy Astrophysical Phenomena, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Event (particle physics), Flare
Abstract: In late 2016 and early 2017 the flat spectrum radio quasar CTA 102 exhibited a very strong and long-lasting outburst. The event can be described by a roughly 2 months long increase of the baseline flux in the monitored energy bands (optical to $\gamma$ rays) by a factor 8, and a subsequent decrease over another 2 months back to pre-flare levels. The long-term trend was superseded by short but very strong flares, resulting in a peak flux that was a factor 50 above pre-flare levels in the $\gamma$-ray domain and almost a factor 100 above pre-flare levels in the optical domain. In this paper we explain the long-term evolution of the outburst by the ablation of a gas cloud penetrating the relativistic jet. The slice-by-slice ablation results in a gradual increase of the particle injection until the center of the cloud is reached, after which the injected number of particles decreases again. With reasonable cloud parameters we obtain excellent fits of the long-term trend., Comment: 9 pages, 5 figures; accepted for publication in The Astrophysical Journal
Published: 2017
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22. Search for TeV Gamma-ray emission from GRB 100621A, an extremely bright GRB in X-rays, with H.E.S.S

Author: Abramowski, A., Aharonian, F., Becker Tjus, J., Lemière, A., Lemoine-Goumard, M., Lenain, J.-P., Lennarz, D., Lohse, T., Lopatin, A., Lu, C.-C., Marandon, V., Marcowith, A., Marx, R., Bernlöhr, K., Maurin, G., Maxted, N., Mayer, Michael, McComb, T. J. L., Méhault, J., Menzler, U., Meyer, M., Moderski, R., Mohamed, M., Moulin, E., Birsin, E., Murach, T., Naumann, C. L., de Naurois, M., Niemiec, J., Nolan, S. J., Oakes, L., O’Brien, P. T., de Oña Wilhelmi, E., Opitz, B., Ostrowski, M., Bissaldi, E., Oya, I., Panter, M., Parsons, R. D., Paz Arribas, M., Pekeur, N. W., Pelletier, G., Perez, J., Petrucci, P.-O., Peyaud, B., Pita, S., Biteau, J., Poon, H., Pühlhofer, G., Punch, M., Quirrenbach, A., Raab, S., Raue, M., Reimer, A., Reimer, O., Renaud, M., de los Reyes, R., Bordas, P., Rieger, F., Rob, L., Romoli, C., Rosier-Lees, S., Rowell, G., Rudak, B., Rulten, C. B., Sahakian, V., Sanchez, D. A., Santangelo, A., Brucker, J., Schlickeiser, R., Schüssler, F., Schulz, A., Schwanke, U., Schwarzburg, S., Schwemmer, S., Sol, H., Spengler, G., Spies, F., Stawarz, Ł., Brun, F., Steenkamp, R., Stegmann, C., Stinzing, F., Stycz, K., Sushch, I., Szostek, A., Tam, P. H. T., Tavernet, J.-P., Tavernier, T., Taylor, A. M., Brun, P., Terrier, R., Tluczykont, M., Trichard, C., Valerius, K., van Eldik, C., Vasileiadis, G., Venter, C., Viana, A., Vincent, P., Völk, H. J., Bulik, T., Volpe, F., Vorster, M., Wagner, P., Ward, M., Weidinger, M., Weitzel, Q., White, R., Wierzcholska, A., Willmann, P., Wörnlein, A., Ait Benkhali, F., Carrigan, S., Wouters, D., Zacharias, M., Zajczyk, A., Zdziarski, A. A., Zech, A., Zechlin, H.-S., H.E.S.S. Collaboration, Böttcher, M., Boisson, C., Bolmont, J., Casanova, S., Conrad, J., Edwards, T., Förster, A., Hahn, J., Ohm, S., Wagner, S. J., Cerruti, M., Chadwick, P. M., Chalme-Calvet, R., Chaves, R. C. G., Cheesebrough, A., Chrétien, M., Colafrancesco, S., Cologna, G., Akhperjanian, A. G., Couturier, C., Dalton, M., Daniel, M. K., Davids, I. D., Degrange, B., Deil, C., deWilt, P., Dickinson, H. J., Djannati-Ataï, A., Domainko, W., Angüner, E., Drury, L. O’C., Dubus, G., Dutson, K., Dyks, J., Dyrda, M., Egberts, K., Eger, P., Espigat, P., Farnier, C., Fegan, S., Anton, G., Feinstein, F., Fernandes, M. V., Fernandez, D., Fiasson, A., Fontaine, G., Füßling, M., Gajdus, M., Gallant, Y. A., Garrigoux, T., Giebels, B., Balenderan, S., Glicenstein, J. F., Grondin, M.-H., Grudzińska, M., Häffner, S., Harris, J., Heinzelmann, G., Henri, G., Hermann, G., Hervet, O., Hillert, A., Balzer, A., Hinton, J. A., Hofmann, W., Hofverberg, P., Holler, M., Horns, D., Jacholkowska, A., Jahn, C., Jamrozy, M., Janiak, M., Jankowsky, F., Barnacka, A., Jung, I., Kastendieck, M. A., Katarzyński, K., Katz, U., Kaufmann, S., Khélifi, B., Kieffer, M., Klepser, S., Klochkov, D., Kluźniak, W., Becherini, Y., Kneiske, T., Kolitzus, D., Komin, Nu., Kosack, K., Krakau, S., Krayzel, F., Krüger, P. P., Laffon, H., Lamanna, G., Lefaucheur, J., H. E. S. S. Collaboration, Laboratoire Leprince-Ringuet (LLR), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique Nucléaire et de Hautes Énergies (LPNHE), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, GLAST, Centre d'Etudes Nucléaires de Bordeaux Gradignan (CENBG), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1 (UB)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), APC - Astrophysique des Hautes Energies (APC - AHE), AstroParticule et Cosmologie (APC (UMR_7164)), 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)-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)-Alma Mater Studiorum Università di Bologna [Bologna] (UNIBO), 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), Laboratoire Univers et Particules de Montpellier (LUPM), Université Montpellier 2 - Sciences et Techniques (UM2)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Annecy de Physique des Particules (LAPP), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), HESS, 12006653 - Venter, Christo, 22050574 - Pekeur, Nicolette Whilna, 12792322 - Vorster, Michael Johannes, 24922986 - Sushch, Iurii, 11749903 - Krüger, Petrus Paulus, 23909196 - Casanova, Sabrina, 24420530 - Böttcher, Markus, Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Pierre et Marie Curie - Paris 6 (UPMC), Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Observatoire de Paris, 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)-Observatoire de Paris, 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)-Dipartimento di Astronomia, Universita degli Studi di Bologna, Alma Mater Studiorum Università di Bologna [Bologna] (UNIBO)-Alma Mater Studiorum Università di Bologna [Bologna] (UNIBO), 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), Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Montpellier 2 - Sciences et Techniques (UM2), 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)-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)-Dipartimento di Astronomia, Universita degli Studi di Bologna, Università di Bologna [Bologna] (UNIBO)-Università di Bologna [Bologna] (UNIBO), PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7), Université de Montpellier (UM)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), and Laboratoire d'Annecy de Physique des Particules (LAPP/Laboratoire d'Annecy-le-Vieux de Physique des Particules)
Subjects: [PHYS.ASTR.HE]Physics [physics]/Astrophysics [astro-ph]/High Energy Astrophysical Phenomena [astro-ph.HE], Gamma rays: general, Gamma rays: stars, Gamma-ray burst: individual: GRB 100621A, X-rays: stars, Astronomy and Astrophysics, Space and Planetary Science, individual: GRB 100621A [Gamma-ray burst], Astrophysics::High Energy Astrophysical Phenomena, stars. [X-rays], Hochenergie-Astrophysik Theorie - Abteilung Hofmann, general [Gamma rays], FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 7. Clean energy, HESS - Abteilung Hofmann, stars [X-rays], Physics, High Energy Astrophysical Phenomena (astro-ph.HE), [SDU.ASTR.HE]Sciences of the Universe [physics]/Astrophysics [astro-ph]/High Energy Astrophysical Phenomena [astro-ph.HE], Gamma ray, stars [Gamma rays], Institut für Physik und Astronomie, GRB 130427A, Cherenkov Telescope Array, Redshift, Afterglow, 13. Climate action, ddc:520, Gamma-ray burst, Astrophysics - High Energy Astrophysical Phenomena, Energy (signal processing), Lepton
Abstract: The long gamma-ray burst (GRB) 100621A, at the time the brightest X-ray transient ever detected by Swift-XRT in the $0.3\textrm{--}10$ keV range, has been observed with the H.E.S.S. imaging air Cherenkov telescope array, sensitive to gamma radiation in the very-high-energy (VHE, $>100$ GeV) regime. Due to its relatively small redshift of $z\sim0.5$, the favourable position in the southern sky and the relatively short follow-up time ($, 8 pages, 2 figures. Published in A&A
Published: 2014
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23. Particle diffusion and localized acceleration in inhomogeneous AGN jets - Part I: Steady-state spectra

Author: Markus Böttcher, Xuhui Chen, Martin Pohl, and 24420530 - Böttcher, Markus
Subjects: Acceleration of particles, Radio galaxy, Astrophysics::High Energy Astrophysical Phenomena, jets [galaxies], FOS: Physical sciences, Electron, non-thermal galaxies [radiation mechanisms], Spectral line, law.invention, Astrophysical jet, law, Blazar, Physics, High Energy Astrophysical Phenomena (astro-ph.HE), diffusion, Institut für Physik und Astronomie, Astronomy and Astrophysics, Synchrotron, Magnetic field, Particle acceleration, Space and Planetary Science, active [galaxies], ddc:520, Atomic physics, Astrophysics - High Energy Astrophysical Phenomena
Abstract: Monthly notices of the Royal Astronomical Society 447(1), 530 - 544 (2015). doi:10.1093/mnras/stu2438, We study the acceleration, transport, and emission of particles in relativistic jets. Localized stochastic particle acceleration, spatial diffusion, and synchrotron as well as synchrotron self-Compton (SSC) emission are considered in a leptonic model. To account for inhomogeneity, we use a 2D axisymmetric cylindrical geometry for both relativistic electrons and magnetic field. In this first phase of our work, we focus on steady-state spectra that develop from a time-dependent model. We demonstrate that small isolated acceleration region in a much larger emission volume are sufficient to accelerate particles to high energy. Diffusive escape from these small regions provides a natural explanation for the spectral form of the jet emission. The location of the acceleration regions within the jet is found to affect the cooling break of the spectrum in this diffusive model. Diffusion-caused energy-dependent inhomogeneity in the jets predicts that the SSC spectrum is harder than the synchrotron spectrum. There can also be a spectral hardening towards the high-energy section of the synchrotron spectrum, if particle escape is relatively slow. These two spectral hardening effects indicate that the jet inhomogeneity might be a natural explanation for the unexpected hard γ-ray spectra observed in some blazars., Published by Oxford Univ. Press, Oxford
Published: 2014
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24. THE VIOLENT HARD X-RAY VARIABILITY OF MRK 421 OBSERVED BYNuSTARIN 2013 APRIL

Author: Vaidehi S. Paliya, Markus Böttcher, Sunder Sahayanathan, C. D. Ravikumar, C. Diltz, C. S. Stalin, and 24420530 - Böttcher, Markus
Subjects: High Energy Astrophysical Phenomena (astro-ph.HE), Physics, Magnetic energy, Event horizon, Astrophysics::High Energy Astrophysical Phenomena, jets [galaxies], FOS: Physical sciences, Astronomy and Astrophysics, Field strength, Astrophysics, Synchrotron, galaxies [X-rays], law.invention, Black hole, Telescope, symbols.namesake, Space and Planetary Science, law, active [galaxies], symbols, Astrophysics - High Energy Astrophysical Phenomena, Blazar, Doppler effect, individual (Mrk 421) [quasars]
Abstract: The well studied blazar Markarian 421 (Mrk 421, $z$=0.031) was the subject of an intensive multi-wavelength campaign when it flared in 2013 April. The recorded X-ray and very high energy (VHE, E$>$100 GeV) $\gamma$-ray fluxes are the highest ever measured from this object. At the peak of the activity, it was monitored by the hard X-ray focusing telescope {\it Nuclear Spectroscopic Telescope Array} ({\it NuSTAR}) and {\it Swift} X-Ray Telescope (XRT). In this work, we present a detailed variability analysis of {\it NuSTAR} and {\it Swift}-XRT observations of Mrk 421 during this flaring episode. We obtained the shortest flux doubling time of 14.01$\pm$5.03 minutes, which is the shortest hard X-ray (3$-$79 keV) variability ever recorded from Mrk 421 and is on the order of the light crossing time of the black hole's event horizon. A pattern of extremely fast variability events superposed on slowly varying flares is found in most of the {\it NuSTAR} observations. We suggest that these peculiar variability patterns may be explained by magnetic energy dissipation and reconnection in a fast moving compact emission region within the jet. Based on the fast variability, we derive a lower limit on the magnetic field strength of $B \ge 0.73 \delta_1^{-2/3} \, \nu_{19}^{1/3}$~G, where $\delta_1$ is the Doppler factor in units of 10, and $\nu_{19}$ is the characteristic X-ray synchrotron frequency in units of $10^{19}$~Hz., Comment: 23 pages, 5 figures, 2 tables, to appear in the Astrophysical Journal
Published: 2015
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25. Probing cluster environments of blazars throughγγabsorption

Author: Markus Böttcher, I. Sushch, 24922986 - Sushch, Iurii, and 24420530 - Böttcher, Markus
Subjects: Physics, general [BL Lacertae objects], Astrophysics::High Energy Astrophysical Phenomena, media_common.quotation_subject, Compton scattering, Astronomy and Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, non-thermal [radiation mechanisms], Universe, Galaxy, Redshift, Stars, individual: 1ES1440+122 [BL Lacertae objects], Extragalactic background light, Space and Planetary Science, Intracluster medium, clusters: general [galaxies], Blazar, Astrophysics::Galaxy Astrophysics, media_common
Abstract: Most blazars are known to be hosted in giant elliptic galaxies, but their cluster environments have not been thoroughly investigated. Cluster environments may contain radiation fields of low-energy photons created by nearby galaxies and/or stars in the intracluster medium that produce diffuse intracluster light. These radiation fields may absorb very high energy γ rays (VHE; E & 100 GeV) and trigger pair cascades with further production of subsequent generations of γ rays with lower energies via inverse Compton scattering on surrounding radiation fields leaving a characteristic imprint in the observed spectral shape. The change of the spectral shape of the blazar reflects the properties of its ambient medium. We show, however, that neither intracluster light nor the radiation field of an individual nearby galaxy can cause substantial γγ absorption. Substantial γγ absorption is possible only in the case of multiple, &5, luminous nearby galaxies. This situation is not found in the local Universe, but may be possible at larger redshifts (z & 2). Since VHE γ rays from such distances are expected to be strongly absorbed by the extragalactic background light, we consider possible signatures of γ-ray induced pair cascades by calculating the expected GeV flux which appears to be below the Fermi-LAT sensitivity even for ∼10 nearby galaxies.
Published: 2014
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26. H.E.S.S. discovery of very-high-energy gamma-ray emission of PKS 1440-389

Author: Yvonne Becherini, Heike Prokoph, Jean-Philippe Lenain, Catherine Boisson, I. Sushch, Markus Böttcher, Laboratoire Univers et Théories (LUTH (UMR_8102)), Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS), H.E.S.S., Laboratoire Univers et Théories ( LUTH ), Institut national des sciences de l'Univers ( INSU - CNRS ) -Observatoire de Paris-Université Paris Diderot - Paris 7 ( UPD7 ) -Centre National de la Recherche Scientifique ( CNRS ), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), 24420530 - Böttcher, Markus, 24922986 - Sushch, Iurii, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)
Subjects: High energy, [ PHYS.ASTR ] Physics [physics]/Astrophysics [astro-ph], Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 7. Clean energy, 01 natural sciences, gamma ray: energy spectrum, GLAST, blazar, HESS, 0103 physical sciences, Gamma ray detectors, gamma ray: detector, Blazar, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, Astroparticle physics, Physics, High Energy Astrophysical Phenomena (astro-ph.HE), 010308 nuclear & particles physics, Compton scattering, Gamma ray, Astronomy, redshift, Redshift, gamma ray: emission, gamma ray: VHE, spectral, Astrophysics - High Energy Astrophysical Phenomena, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract: Blazars are the most abundant class of known extragalactic very-high-energy (VHE, E>100 GeV) gamma-ray sources. However, one of the biggest difficulties in investigating their VHE emission resides in their limited number, since less than 60 of them are known by now. In this contribution we report on H.E.S.S. observations of the BL Lac object PKS 1440-389. This source has been selected as target for H.E.S.S. based on its high-energy gamma-ray properties measured by Fermi-LAT. The extrapolation of this bright, hard-spectrum gamma-ray blazar into the VHE regime made a detection on a relatively short time scale very likely, despite its uncertain redshift. H.E.S.S. observations were carried out with the 4-telescope array from February to May 2012 and resulted in a clear detection of the source. Contemporaneous multi-wavelength data are used to construct the spectral energy distribution of PKS 1440-389 which can be described by a simple one-zone synchrotron-self Compton model., In Proceedings of the 34th International Cosmic Ray Conference (ICRC2015), The Hague, The Netherlands
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27. Monte Carlo Simulations of Compton Polarization in Astrophysical Sources

Author: Lente Dreyer, Böttcher, M., and 24420530 - Böttcher, Markus (Supervisor)
Subjects: Compton polarization, Active galactic nuclei, X-ray binaries, Astrophysics::High Energy Astrophysical Phenomena, Gamma-ray bursts, Monte Carlo, Blazars
Abstract: North-West University, Potchefstroom Campus MSc (Astrophysical Sciences), North-West University, Potchefstroom Campus The description of many high-energy astrophysical sources relies on the production of relativistic jets that are accompanied by the acceleration of particles up to very high energies, and the production of non-thermal radiation (e.g. active galactic nuclei (AGNs), γ-ray bursts (GRBs), X-ray binaries (XRBs), and γ-ray binaries). The radiation from these jet-like sources is characterized by their spectral energy distributions (SEDs), which can be modelled in many different ways, all of which are consistent with the spectral shape of the SED. Discriminating between different models is one of the main objectives in the field of high-energy astrophysics. Compared with the orientation of the relativistic jet, the polarization from the high-energy radiation in astrophysical sources adds crucial knowledge of the jet-physics and jet-formation models. Even though high-energy polarization has remained largely unexplored, the future prospects of detecting polarization in X-rays/soft γ-rays from many astrophysical sources have renewed interest in model predictions of polarization in the high-energy regime. Linear polarization arises from synchrotron radiation of relativistic charged particles in ordered magnetic fields, while Compton scattering off relativistic electrons will reduce the degree of polarization to about half of the target photon polarization. In a model where a thermal and a non-thermal particle distribution scatters an external radiation field, hard X-ray/γ-ray radiation results form relativistic electrons, and the radiation is predicted to be unpolarized. Contrarily, Ultraviolet (UV)/X-ray radiation, resulting from scattering by thermal electrons, is predicted to be polarized. This dissertation describes the development of a Monte Carlo code to study the degree and orientation of Compton polarization in the high-energy regime of jet-like astrophysical sources. Masters

28. High-energy emission from black widows and redbacks

Author: Wadiasingh, Z., Harding, A. K., Christo Venter, Böttcher, M., 12006653 - Venter, Christo, 26594080 - Wadiasingh, Zorawar, and 24420530 - Böttcher, Markus
Subjects: Astrophysics::High Energy Astrophysical Phenomena, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics::Galaxy Astrophysics
Abstract: A large number of new black widow and redback energetic millisecond pulsars with irradiated stellar companions have been discovered through radio searches of unidentified Fermi sources. We construct a 3D emission model of these systems to predict the high-energy emission components from particles accelerated to several TeV in the intrabinary shocks, and its predicted modulation at the binary orbital period. Synchrotron emission is expected at X-ray energies and such modulated emission has already been detected by Chandra and XMM-Newton in some systems. Synchrotron and inverse Compton emission from relativistic particles in the pulsar wind and intrabinary shock can probe the unknown physics of pulsar winds and relativistic shock acceleration in these compact binaries. Orbitally-modulated emission in the GeV and TeV bands may be detectable under some favorable conditions

29. Applying Monte Carlo methods to model multi-wavelength emission of RMHD jet simulations

Author: B. van Soelen, Markus Böttcher, P. J. Meintjes, I. P. van der Westhuizen, and 24420530 - Böttcher, Markus
Subjects: Physics, Jet (fluid), Lorentz factor, symbols.namesake, Photon, Active galactic nucleus, Astrophysical jet, Electromagnetic spectrum, Astrophysics::High Energy Astrophysical Phenomena, Monte Carlo method, Compton scattering, symbols, Computational physics
Abstract: Relativistic jets associated with active galactic nuclei (AGN) produce radiation over a large range of the electromagnetic spectrum. While relativistic magneto-hydrodynamic (RMHD) simulations have become a powerful tool to model the physical structure of jets, in order to correlate them to observations, estimates of the radiation must also be determined. We present the initial results from a study to calculate the multi-wavelength radiation by applying Monte-Carlo methods, using the parameters provided by the RMHD simulations. We present our initial implementation of a Monte Carlo code that interfaces with the RMHD simulation of a steady state axis-symmetric jet created using the PLUTO code. Properties such as the number density, energy density, magnetic field and bulk Lorentz factor are obtained from the RMHD simulations and used to generate a synchrotron photon distribution in each cell. These photons are tracked as they move through the simulation environment and undergoes inverse Compton scattering. Each photon is recorded when it exits the simulation domain and is used to construct multi-wavelength SEDs and light curves. This will provide a time-dependent, multi-zone Synchrotron Self-Compton (SSC) emission model for RMHD simulations.

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29 results on '"24420530 - Böttcher, Markus"'

1. Millimeter-Wave Monitoring of Active Galactic Nuclei with the Africa Millimetre Telescope

2. Optical Variability Modelling Of Newly Identified Blazars And Blazar Candidates Behind Magellanic Clouds

3. gSeaGen: The KM3NeT GENIE-based code for neutrino telescopes

4. Multifrequency observations of the candidate neutrino-emitting blazar BZB J0955+3551

5. Exploiting High-Energy Polarization in Blazars

6. An analytical hadronic synchrotron mirror model forblazars - Application to 3C279

7. Calorimetric Neutrino Expectations from Bright Blazar Flares

8. On the Detection Potential of Blazar Flares for Current Neutrino Telescopes

9. Systematic Physical Characterization of the γ-Ray Spectra of 2FHL Blazars

10. Centaurus A: Hard X-ray and soft gamma-ray lightcurve correlation

11. Why the universe is unexpectedly transparent to very high energy gamma rays

12. VHE γ-ray discovery and multi-wavelength study of the blazar 1ES 2322-409

13. Pressure Balance and Intrabinary Shock Stability in Rotation-Powered State Redback and Transitional Millisecond Pulsar Binary Systems

14. Multi-wavelength observations of flaring blazars with ATOM and Fermi-LAT

15. The Long-Lasting Activity in the Flat Spectrum Radio Quasar (FSRQ) CTA 102

16. PANGU (PAir-productioN Gamma-ray Unit): A High Resolution Gamma-ray Space Telescope

17. First ground-based measurement of sub-20 GeV to 100 GeV γ-Rays from the Vela pulsar with H.E.S.S. II

18. Studies of Relativistic Jets in Active Galactic Nuclei with SKA

19. The high-energy γ-ray emission of AP Librae

20. Nature of Intra-night Optical Variability of BL Lacertae

21. Cloud Ablation by a Relativistic Jet and the Extended Flare in CTA 102 in 2016 and 2017

22. Search for TeV Gamma-ray emission from GRB 100621A, an extremely bright GRB in X-rays, with H.E.S.S

23. Particle diffusion and localized acceleration in inhomogeneous AGN jets - Part I: Steady-state spectra

24. THE VIOLENT HARD X-RAY VARIABILITY OF MRK 421 OBSERVED BYNuSTARIN 2013 APRIL

25. Probing cluster environments of blazars throughγγabsorption

26. H.E.S.S. discovery of very-high-energy gamma-ray emission of PKS 1440-389

27. Monte Carlo Simulations of Compton Polarization in Astrophysical Sources

28. High-energy emission from black widows and redbacks

29. Applying Monte Carlo methods to model multi-wavelength emission of RMHD jet simulations

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29 results on '"24420530 - Böttcher, Markus"'

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