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Simultaneous observations of the blazar PKS 2155−304 from ultra-violet to TeV energies

Abdalla, H. and Adam, R. and Aharonian, F. and Ait Benkhali, F. and Angüner, E. O. and Arakawa, M. and Arcaro, C. and Armand, C. and Ashkar, H. and Backes, M. and Barbosa Martins, V. and Barnard, M. and Becherini, Y. and Berge, D. and Bernlöhr, K. and Blackwell, R. and Böttcher, M. and Boisson, C. and Bolmont, J. and Bonnefoy, S. and Bregeon, J. and Breuhaus, M. and Brun, F. and Brun, P. and Bryan, M. and Büchele, M. and Bulik, T. and Bylund, T. and Caroff, S. and Carosi, A. and Casanova, S. and Cerruti, M. and Chand, T. and Chandra, S. and Chen, A. and Colafrancesco, S. and Curyło, M. and Davids, I. D. and Deil, C. and Devin, J. and deWilt, P. and Dirson, L. and Djannati-Ataï, A. and Dmytriiev, A. and Donath, A. and Doroshenko, V. and Dyks, J. and Egberts, K. and Emery, G. and Ernenwein, J.-P. and Eschbach, S. and Feijen, K. and Fegan, S. and Fiasson, A. and Fontaine, G. and Funk, S. and Füßling, M. and Gabici, S. and Gallant, Y. A. and Gaté, F. and Giavitto, G. and Giunti, L. and Glawion, D. and Glicenstein, J. F. and Gottschall, D. and Grondin, M.-H. and Hahn, J. and Haupt, M. and Heinzelmann, G. and Henri, G. and Hermann, G. and Hinton, J. A. and Hofmann, W. and Hoischen, C. and Holch, T. L. and Holler, M. and Horns, D. and Huber, D. and Iwasaki, H. and Jamrozy, M. and Jankowsky, D. and Jankowsky, F. and Jardin-Blicq, A. and Jung-Richardt, I. and Kastendieck, M. A. and Katarzyński, K. and Katsuragawa, M. and Katz, U. and Khangulyan, D. and Khélifi, B. and King, J. and Klepser, S. and Kluźniak, W. and Komin, Nu. and Kosack, K. and Kostunin, D. and Kreter, M. and Lamanna, G. and Lemière, A. and Lemoine-Goumard, M. and Lenain, J.-P. and Leser, E. and Levy, C. and Lohse, T. and Lypova, I. and Mackey, J. and Majumdar, J. and Malyshev, D. and Marandon, V. and Marcowith, A. and Mares, A. and Mariaud, C. and Martí-Devesa, G. and Marx, R. and Maurin, G. and Meintjes, P. J. and Mitchell, A. M. W. and Moderski, R. and Mohamed, M. and Mohrmann, L. and Moore, C. and Moulin, E. and Muller, J. and Murach, T. and Nakashima, S. and de Naurois, M. and Ndiyavala, H. and Niederwanger, F. and Niemiec, J. and Oakes, L. and O’Brien, P. and Odaka, H. and Ohm, S. and de Ona Wilhelmi, E. and Ostrowski, M. and Oya, I. and Panter, M. and Parsons, R. D. and Perennes, C. and Petrucci, P.-O. and Peyaud, B. and Piel, Q. and Pita, S. and Poireau, V. and Priyana Noel, A. and Prokhorov, D. A. and Prokoph, H. and Pühlhofer, G. and Punch, M. and Quirrenbach, A. and Raab, S. and Rauth, R. and Reimer, A. and Reimer, O. and Remy, Q. and Renaud, M. and Rieger, F. and Rinchiuso, L. and Romoli, C. and Rowell, G. and Rudak, B. and Ruiz-Velasco, E. and Sahakian, V. and Sailer, S. and Saito, S. and Sanchez, D. A. and Santangelo, A. and Sasaki, M. and Schlickeiser, R. and Schüssler, F. and Schulz, A. and Schutte, H. M. and Schwanke, U. and Schwemmer, S. and Seglar-Arroyo, M. and Senniappan, M. and Seyffert, A. S. and Shafi, N. and Shiningayamwe, K. and Simoni, R. and Sinha, A. and Sol, H. and Specovius, A. and Spir-Jacob, M. and Stawarz, Ł. and Steenkamp, R. and Stegmann, C. and Steppa, C. and Takahashi, T. and Tavernier, T. and Taylor, A. M. and Terrier, R. and Tiziani, D. and Tluczykont, M. and Trichard, C. and Tsirou, M. and Tsuji, N. and Tuffs, R. and Uchiyama, Y. and van der Walt, D. J. and van Eldik, C. and van Rensburg, C. and van Soelen, B. and Vasileiadis, G. and Veh, J. and Venter, C. and Vincent, P. and Vink, J. and Völk, H. J. and Vuillaume, T. and Wadiasingh, Z. and Wagner, S. J. and White, R. and Wierzcholska, A. and Yang, R. and Yoneda, H. and Zacharias, M. and Zanin, R. and Zdziarski, A. A. and Zech, A. and Zorn, J. and Żywucka, N. and Madejski, G. M. and Nalewajko, K. and Madsen, K. K. and Chiang, J. and Baloković, M. and Paneque, D. and Furniss, A. K. and Hayashida, M. and Urry, C. M. and Ajello, M. and Harrison, F. A. and Giebels, B. and Stern, D. and Forster, K. and Giommi, P. and Perri, M. and Puccetti, S. and Zoglauer, A. and Tagliaferri, G. (2020) Simultaneous observations of the blazar PKS 2155−304 from ultra-violet to TeV energies. Astronomy and Astrophysics, 639 . Art. No. A42. ISSN 0004-6361. doi:10.1051/0004-6361/201936900.

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Here we report the results of the first ever contemporaneous multi-wavelength observation campaign on the BL Lac object PKS 2155−304 involving Swift, NuSTAR, Fermi-LAT, and H.E.S.S. The use of these instruments allows us to cover a broad energy range, which is important for disentangling the different radiative mechanisms. The source, observed from June 2013 to October 2013, was found in a low flux state with respect to previous observations but exhibited highly significant flux variability in the X-rays. The high-energy end of the synchrotron spectrum can be traced up to 40 keV without significant contamination by high-energy emission. A one-zone synchrotron self-Compton model was used to reproduce the broadband flux of the source for all the observations presented here but failed for previous observations made in April 2013. A lepto-hadronic solution was then explored to explain these earlier observational results.

Item Type:Article
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URLURL TypeDescription Paper
Madsen, K. K.0000-0003-1252-4891
Harrison, F. A.0000-0003-2992-8024
Stern, D.0000-0003-2686-9241
Forster, K.0000-0001-5800-5531
Additional Information:© 2020 H. Abdalla et al. Open Access article, published by EDP Sciences, under the terms of the Creative Commons Attribution License (, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Received 11 October 2019; Accepted 12 December 2019; Published online 07 July 2020. The support of the Namibian authorities and of the University of Namibia in facilitating the construction and operation of H.E.S.S. is gratefully acknowledged, as is the support by the German Ministry for Education and Research (BMBF), the Max Planck Society, the German Research Foundation (DFG), the Helmholtz Association, the Alexander von Humboldt Foundation, the French Ministry of Higher Education, Research and Innovation, the Centre National de la Recherche Scientifique (CNRS/IN2P3 and CNRS/INSU), the Commissariat à l’énergie atomique et aux énergies alternatives (CEA), the U.K. Science and Technology Facilities Council (STFC), the Knut and Alice Wallenberg Foundation, the National Science Centre, Poland grant no. 2016/22/M/ST9/00382, the South African Department of Science and Technology and National Research Foundation, the University of Namibia, the National Commission on Research, Science & Technology of Namibia (NCRST), the Austrian Federal Ministry of Education, Science and Research and the Austrian Science Fund (FWF), the Australian Research Council (ARC), the Japan Society for the Promotion of Science and by the University of Amsterdam. We appreciate the excellent work of the technical support staff in Berlin, Zeuthen, Heidelberg, Palaiseau, Paris, Saclay, Tübingen and in Namibia in the construction and operation of the equipment. This work benefited from services provided by the H.E.S.S. Virtual Organisation, supported by the national resource providers of the EGI Federation. 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 à l’Energie Atomique and the Centre National de la Recherche Scientifique/Institut National de Physique Nucléaire 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 from the following agencies is also gratefully acknowledged: the Istituto Nazionale di Astrofisica in Italy and and the Centre National d’Etudes Spatiales in France. This work performed in part under DOE Contract DE-AC02-76SF00515. This work was supported under NASA Contract No. NNG08FD60C and made use of data from the NuSTAR mission, a project led by the California Institute of Technology, managed by the Jet Propulsion Laboratory, and funded by the National Aeronautics and Space Administration. We thank the NuSTAR Operations, Software, and Calibration teams for support with the execution and analysis of these observations. This research has made use of the NuSTAR Data Analysis Software (NuSTARDAS) jointly developed by the ASI Science Data Center (ASDC, Italy) and the California Institute of Technology (USA). This research has made use of the NASA/IPAC Extragalactic Database (NED) which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration. This research made use of Enrico, a community-developed Python package to simplify Fermi-LAT analysis (Sanchez & Deil 2013). This research has made use of the VizieR catalogue access tool, CDS, Strasbourg, France. The original description of the VizieR service was published in A&AS 143, 23. This work has been done thanks to the facilities offered by the Université Savoie Mont Blanc MUST computing center. M. Cerruti has received financial support through the Postdoctoral Junior Leader Fellowship Programme from la Caixa Banking Foundation, grant n. LCF/BQ/LI18/11630012. M. B. gratefully acknowledges financial support from NASA Headquarters under the NASA Earth and Space Science Fellowship Program (grant NNX14AQ07H), and from the Black Hole Initiative at Harvard University, which is funded through a grant from the John Templeton Foundation.
Group:Astronomy Department, Space Radiation Laboratory
Funding AgencyGrant Number
Bundesministerium für Bildung und Forschung (BMBF)UNSPECIFIED
Max Planck SocietyUNSPECIFIED
Deutsche Forschungsgemeinschaft (DFG)UNSPECIFIED
Helmholtz AssociationUNSPECIFIED
Alexander von Humboldt FoundationUNSPECIFIED
Ministère de l'Enseignement supérieur, de la Recherche et de l'Innovation (MESRI)UNSPECIFIED
Centre National de la Recherche Scientifique (CNRS)UNSPECIFIED
Institut National de Physique Nucléaire et de Physique des Particules (IN2P3)UNSPECIFIED
Centre National de la Recherche Scientifique (CNRS)UNSPECIFIED
Institut National des Sciences de l'Univers (INSU)UNSPECIFIED
Commissariat à l’Énergie Atomique et aux Énergies Alternatives (CEA)UNSPECIFIED
Science and Technology Facilities Council (STFC)UNSPECIFIED
Knut and Alice Wallenberg FoundationUNSPECIFIED
National Science Centre (Poland)2016/22/M/ST9/00382
Department of Science and Technology (South Africa)UNSPECIFIED
National Research Foundation (South Africa)UNSPECIFIED
University of NamibiaUNSPECIFIED
National Commission on Research, Science and Technology (Namibia)UNSPECIFIED
Bundesministerium für Bildung, Wissenschaft, Forschung und Technologie (BMBF)UNSPECIFIED
FWF Der WissenschaftsfondsUNSPECIFIED
Australian Research CouncilUNSPECIFIED
Japan Society for the Promotion of Science (JSPS)UNSPECIFIED
University of AmsterdamUNSPECIFIED
Department of Energy (DOE)DE-AC02-76SF00515
la Caixa Banking FoundationLCF/BQ/LI18/11630012
NASA Earth and Space Science FellowshipNNX14AQ07H
Harvard UniversityUNSPECIFIED
John Templeton FoundationUNSPECIFIED
Subject Keywords:BL Lacertae objects: individual: PKS 2155-304 – astroparticle physics
Record Number:CaltechAUTHORS:20200708-065827527
Persistent URL:
Official Citation:Simultaneous observations of the blazar PKS 2155−304 from ultra-violet to TeV energies. H. Abdalla, et. al. A&A, 639 (2020) A42; DOI:
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:104266
Deposited By: Tony Diaz
Deposited On:08 Jul 2020 15:48
Last Modified:16 Nov 2021 18:30

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