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1. The 2010 very high energy γ-ray flare and 10 years of multi-wavelength observations of M 87

Author

Abramowski, A[, 1, 20, ], Acero, F[ 2 ], Aharonian, F[, 3, 5 ], 4, Akhperjanian, Ag[, 5, 6, ], Anton, G[ 7 ], Balzer, A[ 7 ], Barnacka, A[, 8, 9, ], de Almeida, UB[ 10 ], Becherini, Y[, 11, 12, ], Becker, J[ 13 ], Behera, B[ 14 ], Bernlohr, K[, 3, 15, ], Birsin, E[ 15 ], Biteau, J[ 12 ], Bochow, A[ 3 ], Boisson, C[ 16 ], Bolmont, J[ 17 ], Bordas, P[ 18 ], Brucker, J[ 7 ], Brun, F[ 12 ], Brun, P[ 9 ], Bulik, T[ 19 ], Busching, I[, 13, Carrigan, S[ 3 ], Casanova, S[ 13 ], Cerruti, M[ 16 ], Chadwick, PM[ 10 ], Charbonnier, A[ 17 ], Chaves, RCG[ 3 ], Cheesebrough, A[ 10 ], Clapson, AC[ 3 ], Coignet, G[ 21 ], Cologna, G[ 14 ], Conrad, J[ 22 ], Dalton, M[ 15 ], Daniel, MK[ 10 ], Davids, ID[ 23 ], Degrange, B[ 12 ], Deil, C[ 3 ], Dickinson, HJ[ 22 ], Djannati Atai, A[ 11 ], Domainko, W[ 3 ], Drury, LO[ 4 ], Dubus, G[ 24 ], Dutson, K[ 25 ], Dyks, J[ 8 ], Dyrda, M[ 26 ], Egberts, K[ 27 ], Eger, P[ 7 ], Espigat, P[ 11 ], Fallon, L[ 4 ], Farnier, C[ 2 ], Fegan, S[ 12 ], Feinstein, F[ 2 ], Fernandes, MV[ 1 ], Fiasson, A[ 21 ], Fontaine, G[ 12 ], Forster, A[ 3 ], Fussling, M[ 15 ], Gallant, YA[ 2 ], Gast, H[ 3 ], Gerard, L[ 11 ], Gerbig, D[ 13 ], Giebels, B[ 12 ], Glicenstein, JF[ 9 ], Gluck, B[ 7 ], Goret, P[ 9 ], Goring, D[ 7 ], Haffner, S[ 7 ], Hague, JD[ 3 ], Hampf, D[ 1 ], Hauser, M[ 14 ], Heinz, S[ 7 ], Heinzelmann, G[ 1 ], Henri, G[ 24 ], Hermann, G[ 3 ], Hinton, JA[ 25 ], Hoffmann, A[ 18 ], Hofmann, W[ 3 ], Hofverberg, P[ 3 ], Holler, M[ 7 ], Horns, D[ 1 ], Jacholkowska, A[ 17 ], de Jager, OC[ 20 ], Jahn, C[ 7 ], Jamrozy, M[ 28 ], Jung, I[ 7 ], Kastendieck, MA[ 1 ], Katarzynski, K[ 29 ], Katz, U[ 7 ], Kaufmann, S[ 14 ], Keogh, D[ 10 ], Khangulyan, D[ 3 ], Khelifi, B[ 12 ], Klochkov, D[ 18 ], Kluzniak, W[ 8 ], Kneiske, T[ 1 ], Komin, N[ 21 ], Kosack, K[ 9 ], Kossakowski, R[ 21 ], Laffon, H[ 12 ], Lamanna, G[ 21 ], Lennarz, D[ 3 ], Lohse, T[ 15 ], Lopatin, A[ 7 ], CC[ 3 ], Lu, Marandon, V[ 11 ], Marcowith, A[ 2 ], Masbou, J[ 21 ], Maurin, D[ 17 ], Maxted, N[ 30 ], Mayer, M[ 7 ], Mccomb, TJL[ 10 ], Medina, MC[ 9 ], Mehault, J[ 2 ], Moderski, R[ 8 ], Moulin, E[ 9 ], Naumann, CL[ 17 ], Naumann Godo, M[ 9 ], de Naurois, M[ 12 ], Nedbal, D[ 31 ], Nekrassov, D[ 3 ], Nguyen, N[ 1 ], Nicholas, B[ 30 ], Niemiec, J[ 26 ], Nolan, SJ[ 10 ], Ohm, S[, 3, 32, ], Wilhelmi, ED[ 3 ], Opitz, B[ 1 ], Ostrowski, M[ 28 ], Oya, I[ 15 ], Panter, M[ 3 ], Arribas, MP[ 15 ], Pedaletti, G[ 14 ], Pelletier, G[ 24 ], Petrucci, PO[ 24 ], Pita, S[ 11 ], Puhlhofer, G[ 18 ], Punch, M[ 11 ], Quirrenbach, A[ 14 ], Raue, M[ 1 ], Rayner, SM[ 10 ], Reimer, A[ 27 ], Reimer, O[ 27 ], Renaud, M[ 2 ], de los Reyes, R[ 3 ], Rieger, F[ 3 ], Ripken, J[ 22 ], Rob, L[ 31 ], Rosier Lees, S[ 21 ], Rowell, G[ 30 ], Rudak, B[ 8 ], Rulten, CB[ 10 ], Ruppel, J[ 13 ], Sahakian, V[, 5, Sanchez, DA[ 3 ], Santangelo, A[ 18 ], Schlickeiser, R[ 13 ], Schock, FM[ 7 ], Schulz, A[ 7 ], Schwanke, U[ 15 ], Schwarzburg, S[ 18 ], Schwemmer, S[ 14 ], Sheidaei, F[, 11, Skilton, JL[ 3 ], Sol, H[ 16 ], Spengler, G[ 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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), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Unité Scientifique de la Station de Nançay (USN), Observatoire des Sciences de l'Univers en région Centre (OSUC), 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 d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-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), 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), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG ), Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Joseph Fourier - Grenoble 1 (UJF)-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 Joseph Fourier - Grenoble 1 (UJF)-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)-Centre National d'Études Spatiales [Toulouse] (CNES)-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), HESS, 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), AstroParticule et Cosmologie (APC (UMR_7164)), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7), Laboratoire Univers et Théories (LUTH (UMR_8102)), PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Annecy de Physique des Particules (LAPP/Laboratoire d'Annecy-le-Vieux de Physique des Particules), APC - Astrophysique des Hautes Energies (APC - AHE), 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), Laboratoire d'Astrophysique de Grenoble (LAOG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), 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), Centre National de la Recherche Scientifique (CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO), 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), Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Joseph Fourier - Grenoble 1 (UJF)-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 Joseph Fourier - Grenoble 1 (UJF)-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), Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Abramowski A., Acero F., Aharonian F., Akhperjanian A. G., Anton G., Balzer A., Barnacka A., Barres de Almeida U., Becherini Y., Becker J., Giovannini G., and and 436 coauthors.

Subjects
High energy, UNIFIED SCHEMES, Radio galaxy, [SDU.ASTR.CO]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], VHE [gamma ray], jets [galaxies], nuclei [galaxies], Astrophysics, 7. Clean energy, 01 natural sciences, Spectral line, LARGE-AREA TELESCOPE, law.invention, ACTIVE GALACTIC NUCLEI, SUPERMASSIVE BLACK-HOLE, RADIO GALAXY M87, BASE-LINE ARRAY, TEV EMISSION, CRAB-NEBULA, SCALE JETS, INNER JET, Raigs gamma, law, HESS, flux [gamma ray], black hole, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], MAGIC (telescope), 010303 astronomy & astrophysics, Physics, [PHYS]Physics [physics], flux [X-ray], Gamma ray, radioastronomia, non-thermal [radiation mechanisms], active [galaxies], galaxies [gamma rays], VERITAS, Electrónica, Física nuclear, Electricidad, Flare, Astrophysics - Cosmology and Nongalactic Astrophysics, Cosmology and Nongalactic Astrophysics (astro-ph.CO), galaxies: individual (M 87), Astrophysics::High Energy Astrophysical Phenomena, radio wave [galaxy], galaxies: active, gamma rays: observations, galaxies: jets, radiation mechanisms: non-thermal, FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, gamma ray astronomy, Cosmic rays, IMAGING CHERENKOV DETECTOR, [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], individual: M 87 [galaxies], emission [gamma ray], 0103 physical sciences, gamma rays: galaxies, Astrophysics::Galaxy Astrophysics, galaxies: active , galaxies: individual (M 87) , galaxies: jets , galaxies: nuclei , gamma rays: galaxies , radiation mechanisms: non-thermal, 010308 nuclear & particles physics, Gamma rays, Institut für Physik und Astronomie, Astronomy and Astrophysics, Light curve, Galaxies, MAGIC, Galàxies, Black hole, Space and Planetary Science, ddc:520, time dependence, galaxies: nuclei, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract

著者人数: 444名, Accepted: 2011-11-18, 資料番号: SA1003024000

Published
2012
Full Text
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2. Search for photon-linelike signatures from dark matter annihilations with H.E.S.S.

Author

Abramowski A, Acero F, Aharonian F, Akhperjanian AG, Anton G, Balenderan S, Balzer A, Barnacka A, Becherini Y, Becker Tjus J, Bernlöhr K, Birsin E, Biteau J, Bochow A, Boisson C, Bolmont J, Bordas P, Brucker J, Brun F, Brun P, Bulik T, Carrigan S, Casanova S, Cerruti M, Chadwick PM, Chaves RC, Cheesebrough A, Colafrancesco S, Cologna G, Conrad J, Couturier C, Dalton M, Daniel MK, Davids ID, Degrange B, Deil C, deWilt P, Dickinson HJ, Djannati-Ataï A, Domainko W, Drury LO, Dubus G, Dutson K, Dyks J, Dyrda M, Egberts K, Eger P, Espigat P, Fallon L, Farnier C, Fegan S, Feinstein F, Fernandes MV, Fernandez D, Fiasson A, Fontaine G, Förster A, Füßling M, Gajdus M, Gallant YA, Garrigoux T, Gast H, Giebels B, Glicenstein JF, Glück B, Göring D, Grondin MH, Häffner S, Hague JD, Hahn J, Hampf D, Harris J, Heinz S, Heinzelmann G, Henri G, Hermann G, Hillert A, Hinton JA, Hofmann W, Hofverberg P, Holler M, Horns D, Jacholkowska A, Jahn C, Jamrozy M, Jung I, Kastendieck MA, Katarzyński K, Katz U, Kaufmann S, Khélifi B, Klepser S, Klochkov D, Kluźniak W, Kneiske T, Komin N, Kosack K, Kossakowski R, Krayzel F, Krüger PP, Laffon H, Lamanna G, Lefaucheur J, Lemoine-Goumard M, Lenain JP, Lennarz D, Lohse T, Lopatin A, Lu CC, Marandon V, Marcowith A, Masbou J, Maurin G, Maxted N, Mayer M, McComb TJ, Medina MC, Méhault J, Menzler U, Moderski R, Mohamed M, Moulin E, Naumann CL, Naumann-Godo M, de Naurois M, Nedbal D, Nekrassov D, Nguyen N, Niemiec J, Nolan SJ, Ohm S, de Oña Wilhelmi E, Opitz B, Ostrowski M, Oya I, Panter M, Parsons RD, Paz Arribas M, Pekeur NW, Pelletier G, Perez J, Petrucci PO, Peyaud B, Pita S, Pühlhofer G, Punch M, Quirrenbach A, Raue M, Reimer A, Reimer O, Renaud M, de Los Reyes R, Rieger F, Ripken J, Rob L, Rosier-Lees S, Rowell G, Rudak B, Rulten CB, Sahakian V, Sanchez DA, Santangelo A, Schlickeiser R, Schulz A, Schwanke U, Schwarzburg S, Schwemmer S, Sheidaei F, Skilton JL, Sol H, Spengler G, Stawarz L, Steenkamp R, Stegmann C, Stinzing F, Stycz K, Sushch I, Szostek A, Tavernet JP, Terrier R, Tluczykont M, Trichard C, Valerius K, van Eldik C, Vasileiadis G, Venter C, Viana A, Vincent P, Völk HJ, Volpe F, Vorobiov S, Vorster M, Wagner SJ, Ward M, White R, Wierzcholska A, Wouters D, Zacharias M, Zajczyk A, Zdziarski AA, Zech A, and Zechlin HS

Abstract

Gamma-ray line signatures can be expected in the very-high-energy (E(γ)>100 GeV) domain due to self-annihilation or decay of dark matter (DM) particles in space. Such a signal would be readily distinguishable from astrophysical γ-ray sources that in most cases produce continuous spectra that span over several orders of magnitude in energy. Using data collected with the H.E.S.S. γ-ray instrument, upper limits on linelike emission are obtained in the energy range between ∼ 500 GeV and ∼ 25 TeV for the central part of the Milky Way halo and for extragalactic observations, complementing recent limits obtained with the Fermi-LAT instrument at lower energies. No statistically significant signal could be found. For monochromatic γ-ray line emission, flux limits of (2 × 10(-7) -2 × 10(-5)) m(-2) s(-1) sr(-1) and (1 × 10(-8) -2 × 10(-6)) m(-2) s(-1)sr(-1) are obtained for the central part of the Milky Way halo and extragalactic observations, respectively. For a DM particle mass of 1 TeV, limits on the velocity-averaged DM annihilation cross section ⟨σv⟩(χχ → γγ) reach ∼ 10(-27) cm(3)s(-1), based on the Einasto parametrization of the Galactic DM halo density profile.

Published
2013
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3. Search for a dark matter annihilation signal from the galactic center halo with H.E.S.S.

Author

Abramowski A, Acero F, Aharonian F, Akhperjanian AG, Anton G, Barnacka A, de Almeida UB, Bazer-Bachi AR, Becherini Y, Becker J, Behera B, Bernlöhr K, Bochow A, Boisson C, Bolmont J, Bordas P, Borrel V, Brucker J, Brun F, Brun P, Bulik T, Büsching I, Carrigan S, Casanova S, Cerruti M, Chadwick PM, Charbonnier A, Chaves RC, Cheesebrough A, Chounet LM, Clapson AC, Coignet G, Conrad J, Dalton M, Daniel MK, Davids ID, Degrange B, Deil C, Dickinson HJ, Djannati-Ataï A, Domainko W, Drury LO, Dubois F, Dubus G, Dyks J, Dyrda M, Egberts K, Eger P, Espigat P, Fallon L, Farnier C, Fegan S, Feinstein F, Fernandes MV, Fiasson A, Fontaine G, Förster A, Füssling M, Gallant YA, Gast H, Gérard L, Gerbig D, Giebels B, Glicenstein JF, Glück B, Goret P, Göring D, Hague JD, Hampf D, Hauser M, Heinz S, Heinzelmann G, Henri G, Hermann G, Hinton JA, Hoffmann A, Hofmann W, Hofverberg P, Horns D, Jacholkowska A, de Jager OC, Jahn C, Jamrozy M, Jung I, Kastendieck MA, Katarzyński K, Katz U, Kaufmann S, Keogh D, Kerschhaggl M, Khangulyan D, Khélifi B, Klochkov D, Kluźniak W, Kneiske T, Komin N, Kosack K, Kossakowski R, Laffon H, Lamanna G, Lennarz D, Lohse T, Lopatin A, Lu CC, Marandon V, Marcowith A, Masbou J, Maurin D, Maxted N, McComb TJ, Medina MC, Méhault J, Moderski R, Moulin E, Naumann CL, Naumann-Godo M, de Naurois M, Nedbal D, Nekrassov D, Nguyen N, Nicholas B, Niemiec J, Nolan SJ, Ohm S, Olive JF, Wilhelmi Ede O, Opitz B, Ostrowski M, Panter M, Arribas MP, Pedaletti G, Pelletier G, Petrucci PO, Pita S, Pühlhofer G, Punch M, Quirrenbach A, Raue M, Rayner SM, Reimer A, Reimer O, Renaud M, de los Reyes R, Rieger F, Ripken J, Rob L, Rosier-Lees S, Rowell G, Rudak B, Rulten CB, Ruppel J, Ryde F, Sahakian V, Santangelo A, Schlickeiser R, Schöck FM, Schönwald A, Schwanke U, Schwarzburg S, Schwemmer S, Shalchi A, Sikora M, Skilton JL, Sol H, Spengler G, Stawarz Ł, Steenkamp R, Stegmann C, Stinzing F, Sushch I, Szostek A, Tavernet JP, Terrier R, Tibolla O, Tluczykont M, Valerius K, van Eldik C, Vasileiadis G, Venter C, Vialle JP, Viana A, Vincent P, Vivier M, Völk HJ, Volpe F, Vorobiov S, Vorster M, Wagner SJ, Ward M, Wierzcholska A, Zajczyk A, Zdziarski AA, Zech A, and Zechlin HS

Abstract

A search for a very-high-energy (VHE; ≥100  GeV) γ-ray signal from self-annihilating particle dark matter (DM) is performed towards a region of projected distance r∼45-150  pc from the Galactic center. The background-subtracted γ-ray spectrum measured with the High Energy Stereoscopic System (H.E.S.S.) γ-ray instrument in the energy range between 300 GeV and 30 TeV shows no hint of a residual γ-ray flux. Assuming conventional Navarro-Frenk-White and Einasto density profiles, limits are derived on the velocity-weighted annihilation cross section (σv) as a function of the DM particle mass. These are among the best reported so far for this energy range and in particular differ only little between the chosen density profile parametrizations. In particular, for the DM particle mass of ∼1  TeV, values for (σv) above 3×10(-25)  cm(3) s(-1) are excluded for the Einasto density profile.

Published
2011
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4. Detection of gamma rays from a starburst galaxy.

Author

Acero F, Aharonian F, Akhperjanian AG, Anton G, Barres de Almeida U, Bazer-Bachi AR, Becherini Y, Behera B, Bernlöhr K, Bochow A, Boisson C, Bolmont J, Borrel V, Brucker J, Brun F, Brun P, Bühler R, Bulik T, Büsching I, Boutelier T, Chadwick PM, Charbonnier A, Chaves RC, Cheesebrough A, Chounet LM, Clapson AC, Coignet G, Dalton M, Daniel MK, Davids ID, Degrange B, Deil C, Dickinson HJ, Djannati-Ataï A, Domainko W, Drury LO, Dubois F, Dubus G, Dyks J, Dyrda M, Egberts K, Emmanoulopoulos D, Espigat P, Farnier C, Fegan S, Feinstein F, Fiasson A, Förster A, Fontaine G, Füssling M, Gabici S, Gallant YA, Gérard L, Gerbig D, Giebels B, Glicenstein JF, Glück B, Goret P, Göring D, Hauser D, Hauser M, Heinz S, Heinzelmann G, Henri G, Hermann G, Hinton JA, Hoffmann A, Hofmann W, Hofverberg P, Hoppe S, Horns D, Jacholkowska A, de Jager OC, Jahn C, Jung I, Katarzyński K, Katz U, Kaufmann S, Kerschhaggl M, Khangulyan D, Khélifi B, Keogh D, Klochkov D, Kluźniak W, Kneiske T, Komin N, Kosack K, Kossakowski R, Lamanna G, Lenain JP, Lohse T, Marandon V, Martineau-Huynh O, Marcowith A, Masbou J, Maurin D, McComb TJ, Medina MC, Méhault J, Moderski R, Moulin E, Naumann-Godo M, de Naurois M, Nedbal D, Nekrassov D, Nicholas B, Niemiec J, Nolan SJ, Ohm S, Olive JF, de Oña Wilhelmi E, Orford KJ, Ostrowski M, Panter M, Paz Arribas M, Pedaletti G, Pelletier G, Petrucci PO, Pita S, Pühlhofer G, Punch M, Quirrenbach A, Raubenheimer BC, Raue M, Rayner SM, Reimer O, Renaud M, Rieger F, Ripken J, Rob L, Rosier-Lees S, Rowell G, Rudak B, Rulten CB, Ruppel J, Sahakian V, Santangelo A, Schlickeiser R, Schöck FM, Schwanke U, Schwarzburg S, Schwemmer S, Shalchi A, Sikora M, Skilton JL, Sol H, Stawarz Ł, Steenkamp R, Stegmann C, Stinzing F, Superina G, Szostek A, Tam PH, Tavernet JP, Terrier R, Tibolla O, Tluczykont M, van Eldik C, Vasileiadis G, Venter C, Venter L, Vialle JP, Vincent P, Vivier M, Völk HJ, Volpe F, Wagner SJ, Ward M, Zdziarski AA, and Zech A

Abstract

Starburst galaxies exhibit in their central regions a highly increased rate of supernovae, the remnants of which are thought to accelerate energetic cosmic rays up to energies of approximately 10(15) electron volts. We report the detection of gamma rays--tracers of such cosmic rays--from the starburst galaxy NGC 253 using the High Energy Stereoscopic System (H.E.S.S.) array of imaging atmospheric Cherenkov telescopes. The gamma-ray flux above 220 billion electron volts is F = (5.5 +/- 1.0(stat) +/- 2.8(sys)) x 10(-13) cm(-2) s(-1), implying a cosmic-ray density about three orders of magnitude larger than that in the center of the Milky Way. The fraction of cosmic-ray energy channeled into gamma rays in this starburst environment is five times as large as that in our Galaxy.

Published
2009
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5. Radio imaging of the very-high-energy gamma-ray emission region in the central engine of a radio galaxy.

Author

Acciari VA, Aliu E, Arlen T, Bautista M, Beilicke M, Benbow W, Bradbury SM, Buckley JH, Bugaev V, Butt Y, Byrum K, Cannon A, Celik O, Cesarini A, Chow YC, Ciupik L, Cogan P, Cui W, Dickherber R, Fegan SJ, Finley JP, Fortin P, Fortson L, Furniss A, Gall D, Gillanders GH, Grube J, Guenette R, Gyuk G, Hanna D, Holder J, Horan D, Hui CM, Humensky TB, Imran A, Kaaret P, Karlsson N, Kieda D, Kildea J, Konopelko A, Krawczynski H, Krennrich F, Lang MJ, LeBohec S, Maier G, McCann A, McCutcheon M, Millis J, Moriarty P, Ong RA, Otte AN, Pandel D, Perkins JS, Petry D, Pohl M, Quinn J, Ragan K, Reyes LC, Reynolds PT, Roache E, Roache E, Rose HJ, Schroedter M, Sembroski GH, Smith AW, Swordy SP, Theiling M, Toner JA, Varlotta A, Vincent S, Wakely SP, Ward JE, Weekes TC, Weinstein A, Williams DA, Wissel S, Wood M, Walker RC, Davies F, Hardee PE, Junor W, Ly C, Aharonian F, Akhperjanian AG, Anton G, Barres de Almeida U, Bazer-Bachi AR, Becherini Y, Behera B, Bernlöhr K, Bochow A, Boisson C, Bolmont J, Borrel V, Brucker J, Brun F, Brun P, Bühler R, Bulik T, Büsching I, Boutelier T, Chadwick PM, Charbonnier A, Chaves RC, Cheesebrough A, Chounet LM, Clapson AC, Coignet G, Dalton M, Daniel MK, Davids ID, Degrange B, Deil C, Dickinson HJ, Djannati-Ataï A, Domainko W, Drury LO, Dubois F, Dubus G, Dyks J, Dyrda M, Egberts K, Emmanoulopoulos D, Espigat P, Farnier C, Feinstein F, Fiasson A, Förster A, Fontaine G, Füssling M, Gabici S, Gallant YA, Gérard L, Gerbig D, Giebels B, Glicenstein JF, Glück B, Goret P, Göhring D, Hauser D, Hauser M, Heinz S, Heinzelmann G, Henri G, Hermann G, Hinton JA, Hoffmann A, Hofmann W, Holleran M, Hoppe S, Horns D, Jacholkowska A, de Jager OC, Jahn C, Jung I, Katarzyński K, Katz U, Kaufmann S, Kendziorra E, Kerschhaggl M, Khangulyan D, Khélifi B, Keogh D, Kluźniak W, Kneiske T, Komin N, Kosack K, Lamanna G, Lenain JP, Lohse T, Marandon V, Martin JM, Martineau-Huynh O, Marcowith A, Maurin D, McComb TJ, Medina MC, Moderski R, Moulin E, Naumann-Godo M, de Naurois M, Nedbal D, Nekrassov D, Nicholas B, Niemiec J, Nolan SJ, Ohm S, Olive JF, de Oña Wilhelmi E, Orford KJ, Ostrowski M, Panter M, Paz Arribas M, Pedaletti G, Pelletier G, Petrucci PO, Pita S, Pühlhofer G, Punch M, Quirrenbach A, Raubenheimer BC, Raue M, Rayner SM, Renaud M, Rieger F, Ripken J, Rob L, Rosier-Lees S, Rowell G, Rudak B, Rulten CB, Ruppel J, Sahakian V, Santangelo A, Schlickeiser R, Schöck FM, Schröder R, Schwanke U, Schwarzburg S, Schwemmer S, Shalchi A, Sikora M, Skilton JL, Sol H, Spangler D, Stawarz Ł, Steenkamp R, Stegmann C, Stinzing F, Superina G, Szostek A, Tam PH, Tavernet JP, Terrier R, Tibolla O, Tluczykont M, van Eldik C, Vasileiadis G, Venter C, Venter L, Vialle JP, Vincent P, Vivier M, Völk HJ, Volpe F, Wagner SJ, Ward M, Zdziarski AA, Zech A, Anderhub H, Antonelli LA, Antoranz P, Backes M, Baixeras C, Balestra S, Barrio JA, Bastieri D, Becerra González J, Becker JK, Bednarek W, Berger K, Bernardini E, Biland A, Bock RK, Bonnoli G, Bordas P, Borla Tridon D, Bosch-Ramon V, Bose D, Braun I, Bretz T, Britvitch I, Camara M, Carmona E, Commichau S, Contreras JL, Cortina J, Costado MT, Covino S, Curtef V, Dazzi F, De Angelis A, De Cea del Pozo E, Delgado Mendez C, De los Reyes R, De Lotto B, De Maria M, De Sabata F, Dominguez A, Dorner D, Doro M, Elsaesser D, Errando M, Ferenc D, Fernández E, Firpo R, Fonseca MV, Font L, Galante N, García López RJ, Garczarczyk M, Gaug M, Goebel F, Hadasch D, Hayashida M, Herrero A, Hildebrand D, Höhne-Mönch D, Hose J, Hsu CC, Jogler T, Kranich D, La Barbera A, Laille A, Leonardo E, Lindfors E, Lombardi S, Longo F, López M, Lorenz E, Majumdar P, Maneva G, Mankuzhiyil N, Mannheim K, Maraschi L, Mariotti M, Martínez M, Mazin D, Meucci M, Miranda JM, Mirzoyan R, Miyamoto H, Moldón J, Moles M, Moralejo A, Nieto D, Nilsson K, Ninkovic J, Oya I, Paoletti R, Paredes JM, Pasanen M, Pascoli D, Pauss F, Pegna RG, Perez-Torres MA, Persic M, Peruzzo L, Prada F, Prandini E, Puchades N, Reichardt I, Rhode W, Ribó M, Rico J, Rissi M, Robert A, Rügamer S, Saggion A, Saito TY, Salvati M, Sanchez-Conde M, Satalecka K, Scalzotto V, Scapin V, Schweizer T, Shayduk M, Shore SN, Sidro N, Sierpowska-Bartosik A, Sillanpää A, Sitarek J, Sobczynska D, Spanier F, Stamerra A, Stark LS, Takalo L, Tavecchio F, Temnikov P, Tescaro D, Teshima M, Torres DF, Turini N, Vankov H, Wagner RM, Zabalza V, Zandanel F, Zanin R, and Zapatero J

Abstract

The accretion of matter onto a massive black hole is believed to feed the relativistic plasma jets found in many active galactic nuclei (AGN). Although some AGN accelerate particles to energies exceeding 10(12) electron volts and are bright sources of very-high-energy (VHE) gamma-ray emission, it is not yet known where the VHE emission originates. Here we report on radio and VHE observations of the radio galaxy Messier 87, revealing a period of extremely strong VHE gamma-ray flares accompanied by a strong increase of the radio flux from its nucleus. These results imply that charged particles are accelerated to very high energies in the immediate vicinity of the black hole.

Published
2009
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6. Energy spectrum of cosmic-ray electrons at TeV energies.

Author

Aharonian F, Akhperjanian AG, Barres de Almeida U, Bazer-Bachi AR, Becherini Y, Behera B, Benbow W, Bernlöhr K, Boisson C, Bochow A, Borrel V, Braun I, Brion E, Brucker J, Brun P, Brucker R, Bulik T, Büsching I, Boutelier T, Carrigan S, Chadwick PM, Charbonnier A, Chaves RC, Cheesebrough A, Chounet LM, Clapson AC, Coignet G, Costamante L, Dalton M, Degrange B, Deil C, Dickinson HJ, Djannati-Ataï A, Domainko W, Drury LO, Dubois F, Dubus G, Dyks J, Dyrda M, Egberts K, Emmanoulopoulos D, Espigat P, Farnier C, Feinstein F, Fiasson A, Fontaine G, Füsling M, Gabici S, Gallant YA, Gérard L, Giebels B, Glicenstein JF, Glück B, Goret P, Hadjichristidis C, Hauser D, Hauser M, Heinz S, Heinzelmann G, Henri G, Hermann G, Hinton JA, Hoffmann A, Hofmann W, Holleran M, Hoppe S, Horns D, Jacholkowska A, de Jager OC, Jung I, Katarzyński K, Kaufmann S, Kendziorra E, Kerschhaggl M, Khangulyan D, Khélifi B, Keogh D, Komin N, Kosack K, Lamanna G, Lenain JP, Lohse T, Marandon V, Martin JM, Martineau-Huynh O, Marcowith A, Maurin D, McComb TJ, Medina C, Moderski R, Moulin E, Naumann-Godo M, de Naurois M, Nedbal D, Nekrassov D, Niemiec J, Nolan SJ, Ohm S, Olive JF, de Oña Wilhelmi E, Orford KJ, Osborne JL, Ostrowski M, Panter M, Pedaletti G, Pelletier G, Petrucci PO, Pita S, Pühlhofer G, Punch M, Quirrenbach A, Raubenheimer BC, Raue M, Rayner SM, Renaud M, Rieger F, Ripken J, Rob L, Rosier-Lees S, Rowell G, Rudak B, Rulten CB, Ruppel J, Sahakian V, Santangelo A, Schlickeiser R, Schöck FM, Schröder R, Schwanke U, Schwarzburg S, Schwemmer S, Shalchi A, Skilton JL, Sol H, Spangler D, Stawarz Ł, Steenkamp R, Stegmann C, Superina G, Tam PH, Tavernet JP, Terrier R, Tibolla O, van Eldik C, Vasileiadis G, Venter C, Vialle JP, Vincent P, Vivier M, Völk HJ, Volpe F, Wagner SJ, Ward M, Zdziarski AA, and Zech A

Abstract

The very large collection area of ground-based gamma-ray telescopes gives them a substantial advantage over balloon or satellite based instruments in the detection of very-high-energy (>600 GeV) cosmic-ray electrons. Here we present the electron spectrum derived from data taken with the High Energy Stereoscopic System (H.E.S.S.) of imaging atmospheric Cherenkov telescopes. In this measurement, the first of this type, we are able to extend the measurement of the electron spectrum beyond the range accessible to direct measurements. We find evidence for a substantial steepening in the energy spectrum above 600 GeV compared to lower energies.

Published
2008
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7. Limits on an energy dependence of the speed of light from a flare of the active galaxy PKS 2155-304.

Author

Aharonian F, Akhperjanian AG, Barres de Almeida U, Bazer-Bachi AR, Becherini Y, Behera B, Beilicke M, Benbow W, Bernlöhr K, Boisson C, Bochow A, Borrel V, Braun I, Brion E, Brucker J, Brun P, Bühler R, Bulik T, Büsching I, Boutelier T, Carrigan S, Chadwick PM, Charbonnier A, Chaves RC, Chounet LM, Clapson AC, Coignet G, Costamante L, Dalton M, Degrange B, Deil C, Dickinson HJ, Djannati-Ataï A, Domainko W, Drury LO, Dubois F, Dubus G, Dyks J, Egberts K, Emmanoulopoulos D, Espigat P, Farnier C, Feinstein F, Fiasson A, Förster A, Fontaine G, Füssling M, Gabici S, Gallant YA, Gérard L, Giebels B, Glicenstein JF, Glück B, Goret P, Hadjichristidis C, Hauser D, Hauser M, Heinz S, Heinzelmann G, Henri G, Hermann G, Hinton JA, Hoffmann A, Hofmann W, Holleran M, Hoppe S, Horns D, Jacholkowska A, de Jager OC, Jung I, Katarzyński K, Kaufmann S, Kendziorra E, Kerschhaggl M, Khangulyan D, Khélifi B, Keogh D, Komin N, Kosack K, Lamanna G, Lenain JP, Lohse T, Marandon V, Martin JM, Martineau-Huynh O, Marcowith A, Maurin D, McComb TJ, Medina C, Moderski R, Moulin E, Naumann-Godo M, de Naurois M, Nedbal D, Nekrassov D, Niemiec J, Nolan SJ, Ohm S, Olive JF, de Oña Wilhelmi E, Orford KJ, Osborne JL, Ostrowski M, Panter M, Pedaletti G, Pelletier G, Petrucci PO, Pita S, Pühlhofer G, Punch M, Quirrenbach A, Raubenheimer BC, Raue M, Rayner SM, Renaud M, Rieger F, Ripken J, Rob L, Rosier-Lees S, Rowell G, Rudak B, Ruppel J, Sahakian V, Santangelo A, Schlickeiser R, Schöck FM, Schröder R, Schwanke U, Schwarzburg S, Schwemmer S, Shalchi A, Skilton JL, Sol H, Spangler D, Stawarz Ł, Steenkamp R, Stegmann C, Superina G, Tam PH, Tavernet JP, Terrier R, Tibolla O, van Eldik C, Vasileiadis G, Venter C, Vialle JP, Vincent P, Vivier M, Völk HJ, Volpe F, Wagner SJ, Ward M, Zdziarski AA, and Zech A

Abstract

In the past few decades, several models have predicted an energy dependence of the speed of light in the context of quantum gravity. For cosmological sources such as active galaxies, this minuscule effect can add up to measurable photon-energy dependent time lags. In this Letter a search for such time lags during the High Energy Stereoscopic System observations of the exceptional very high energy flare of the active galaxy PKS 2155-304 on 28 July 2006 is presented. Since no significant time lag is found, lower limits on the energy scale of speed of light modifications are derived.

Published
2008
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8. HESS observations of the galactic center region and their possible dark matter interpretation.

Author

Aharonian F, Akhperjanian AG, Bazer-Bachi AR, Beilicke M, Benbow W, Berge D, Bernlöhr K, Boisson C, Bolz O, Borrel V, Braun I, Breitling F, Brown AM, Bühler R, Büsching I, Carrigan S, Chadwick PM, Chounet LM, Cornils R, Costamante L, Degrange B, Dickinson HJ, Djannati-Ataï A, Drury LO, Dubus G, Egberts K, Emmanoulopoulos D, Espigat P, Feinstein F, Ferrero E, Fiasson A, Fontaine G, Funk S, Funk S, Gallant YA, Giebels B, Glicenstein JF, Goret P, Hadjichristidis C, Hauser D, Hauser M, Heinzelmann G, Henri G, Hermann G, Hinton JA, Hofmann W, Holleran M, Horns D, Jacholkowska A, de Jager OC, Khélifi B, Komin N, Konopelko A, Kosack K, Latham IJ, Le Gallou R, Lemière A, Lemoine-Goumard M, Lohse T, Martin JM, Martineau-Huynh O, Marcowith A, Masterson C, McComb TJ, de Naurois M, Nedbal D, Nolan SJ, Noutsos A, Orford KJ, Osborne JL, Ouchrif M, Panter M, Pelletier G, Pita S, Pühlhofer G, Punch M, Raubenheimer BC, Raue M, Rayner SM, Reimer A, Reimer O, Ripken J, Rob L, Rolland L, Rowell G, Sahakian V, Saugé L, Schlenker S, Schlickeiser R, Schwanke U, Sol H, Spangler D, Spanier F, Steenkamp R, Stegmann C, Superina G, Tavernet JP, Terrier R, Théoret CG, Tluczykont M, van Eldik C, Vasileiadis G, Venter C, Vincent P, Völk HJ, Wagner SJ, and Ward M

Abstract

The detection of gamma rays from the source HESS J1745-290 in the Galactic Center (GC) region with the High Energy Spectroscopic System (HESS) array of Cherenkov telescopes in 2004 is presented. After subtraction of the diffuse gamma-ray emission from the GC ridge, the source is compatible with a point source with spatial extent less than 1.2;{'}(stat) (95% C.L.). The measured energy spectrum above 160 GeV is compatible with a power law with photon index of 2.25+/-0.04(stat)+/-0.10(syst) and no significant flux variation is detected. It is finally found that the bulk of the very high energy emission must have non-dark-matter origin.

Published
2006
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9. Fast variability of tera-electron volt gamma rays from the radio galaxy M87.

Author

Aharonian F, Akhperjanian AG, Bazer-Bachi AR, Beilicke M, Benbow W, Berge D, Bernlöhr K, Boisson C, Bolz O, Borrel V, Braun I, Brown AM, Bühler R, Büsching I, Carrigan S, Chadwick PM, Chounet LM, Coignet G, Cornils R, Costamante L, Degrange B, Dickinson HJ, Djannati-Ataï A, Drury LO, Dubus G, Egberts K, Emmanoulopoulos D, Espigat P, Feinstein F, Ferrero E, Fiasson A, Fontaine G, Funk S, Funk S, Füssling M, Gallant YA, Giebels B, Glicenstein JF, Goret P, Hadjichristidis C, Hauser D, Hauser M, Heinzelmann G, Henri G, Hermann G, Hinton JA, Hoffmann A, Hofmann W, Holleran M, Hoppe S, Horns D, Jacholkowska A, de Jager OC, Kendziorra E, Kerschhaggl M, Khélifi B, Komin N, Konopelko A, Kosack K, Lamanna G, Latham IJ, Le Gallou R, Lemière A, Lemoine-Goumard M, Lenain JP, Lohse T, Martin JM, Martineau-Huynh O, Marcowith A, Masterson C, Maurin G, McComb TJ, Moulin E, de Naurois M, Nedbal D, Nolan SJ, Noutsos A, Orford KJ, Osborne JL, Ouchrif M, Panter M, Pelletier G, Pita S, Pühlhofer G, Punch M, Ranchon S, Raubenheimer BC, Raue M, Rayner SM, Reimer A, Ripken J, Rob L, Rolland L, Rosier-Lees S, Rowell G, Sahakian V, Santangelo A, Saugé L, Schlenker S, Schlickeiser R, Schröder R, Schwanke U, Schwarzburg S, Schwemmer S, Shalchi A, Sol H, Spangler D, Spanier F, Steenkamp R, Stegmann C, Superina G, Tam PH, Tavernet JP, Terrier R, Tluczykont M, van Eldik C, Vasileiadis G, Venter C, Vialle JP, Vincent P, Völk HJ, Wagner SJ, and Ward M

Abstract

The detection of fast variations of the tera-electron volt (TeV) (10(12) eV) gamma-ray flux, on time scales of days, from the nearby radio galaxy M87 is reported. These variations are about 10 times as fast as those observed in any other wave band and imply a very compact emission region with a dimension similar to the Schwarzschild radius of the central black hole. We thus can exclude several other sites and processes of the gamma-ray production. The observations confirm that TeV gamma rays are emitted by extragalactic sources other than blazars, where jets are not relativistically beamed toward the observer.

Published
2006
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10. A low level of extragalactic background light as revealed by gamma-rays from blazars.

Author

Aharonian F, Akhperjanian AG, Bazer-Bachi AR, Beilicke M, Benbow W, Berge D, Bernlöhr K, Boisson C, Bolz O, Borrel V, Braun I, Breitling F, Brown AM, Chadwick PM, Chounet LM, Cornils R, Costamante L, Degrange B, Dickinson HJ, Djannati-Ataï A, Drury LO, Dubus G, Emmanoulopoulos D, Espigat P, Feinstein F, Fontaine G, Fuchs Y, Funk S, Gallant YA, Giebels B, Gillessen S, Glicenstein JF, Goret P, Hadjichristidis C, Hauser D, Hauser M, Heinzelmann G, Henri G, Hermann G, Hinton JA, Hofmann W, Holleran M, Horns D, Jacholkowska A, de Jager OC, Khélifi B, Klages S, Komin N, Konopelko A, Latham IJ, Le Gallou R, Lemière A, Lemoine-Goumard M, Leroy N, Lohse T, Martin JM, Martineau-Huynh O, Marcowith A, Masterson C, McComb TJ, de Naurois M, Nolan SJ, Noutsos A, Orford KJ, Osborne JL, Ouchrif M, Panter M, Pelletier G, Pita S, Pühlhofer G, Punch M, Raubenheimer BC, Raue M, Raux J, Rayner SM, Reimer A, Reimer O, Ripken J, Rob L, Rolland L, Rowell G, Sahakian V, Saugé L, Schlenker S, Schlickeiser R, Schuster C, Schwanke U, Siewert M, Sol H, Spangler D, Steenkamp R, Stegmann C, Tavernet JP, Terrier R, Théoret CG, Tluczykont M, van Eldik C, Vasileiadis G, Venter C, Vincent P, Völk HJ, and Wagner SJ

Abstract

The diffuse extragalactic background light consists of the sum of the starlight emitted by galaxies through the history of the Universe, and it could also have an important contribution from the 'first stars', which may have formed before galaxy formation began. Direct measurements are difficult and not yet conclusive, owing to the large uncertainties caused by the bright foreground emission associated with zodiacal light. An alternative approach is to study the absorption features imprinted on the gamma-ray spectra of distant extragalactic objects by interactions of those photons with the background light photons. Here we report the discovery of gamma-ray emission from the blazars H 2356 - 309 and 1ES 1101 - 232, at redshifts z = 0.165 and z = 0.186, respectively. Their unexpectedly hard spectra provide an upper limit on the background light at optical/near-infrared wavelengths that appears to be very close to the lower limit given by the integrated light of resolved galaxies. The background flux at these wavelengths accordingly seems to be strongly dominated by the direct starlight from galaxies, thus excluding a large contribution from other sources-in particular from the first stars formed. This result also indicates that intergalactic space is more transparent to gamma-rays than previously thought.

Published
2006
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11. Discovery of very-high-energy gamma-rays from the Galactic Centre ridge.

Author

Aharonian F, Akhperjanian AG, Bazer-Bachi AR, Beilicke M, Benbow W, Berge D, Bernlöhr K, Boisson C, Bolz O, Borrel V, Braun I, Breitling F, Brown AM, Chadwick PM, Chounet LM, Cornils R, Costamante L, Degrange B, Dickinson HJ, Djannati-Ataï A, Drury LO, Dubus G, Emmanoulopoulos D, Espigat P, Feinstein F, Fontaine G, Fuchs Y, Funk S, Gallant YA, Giebels B, Gillessen S, Glicenstein JF, Goret P, Hadjichristidis C, Hauser D, Hauser M, Heinzelmann G, Henri G, Hermann G, Hinton JA, Hofmann W, Holleran M, Horns D, Jacholkowska A, de Jager OC, Khélifi B, Klages S, Komin N, Konopelko A, Latham IJ, Le Gallou R, Lemière A, Lemoine-Goumard M, Leroy N, Lohse T, Marcowith A, Martin JM, Martineau-Huynh O, Masterson C, McComb TJ, de Naurois M, Nolan SJ, Noutsos A, Orford KJ, Osborne JL, Ouchrif M, Panter M, Pelletier G, Pita S, Pühlhofer G, Punch M, Raubenheimer BC, Raue M, Raux J, Rayner SM, Reimer A, Reimer O, Ripken J, Rob L, Rolland L, Rowell G, Sahakian V, Saugé L, Schlenker S, Schlickeiser R, Schuster C, Schwanke U, Siewert M, Sol H, Spangler D, Steenkamp R, Stegmann C, Tavernet JP, Terrier R, Théoret CG, Tluczykont M, van Eldik C, Vasileiadis G, Venter C, Vincent P, Völk HJ, and Wagner SJ

Abstract

The source of Galactic cosmic rays (with energies up to 10(15) eV) remains unclear, although it is widely believed that they originate in the shock waves of expanding supernova remnants. At present the best way to investigate their acceleration and propagation is by observing the gamma-rays produced when cosmic rays interact with interstellar gas. Here we report observations of an extended region of very-high-energy (> 10(11) eV) gamma-ray emission correlated spatially with a complex of giant molecular clouds in the central 200 parsecs of the Milky Way. The hardness of the gamma-ray spectrum and the conditions in those molecular clouds indicate that the cosmic rays giving rise to the gamma-rays are likely to be protons and nuclei rather than electrons. The energy associated with the cosmic rays could have come from a single supernova explosion around 10(4) years ago.

Published
2006
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12. Discovery of very high energy gamma rays associated with an x-ray binary.

Author

Aharonian F, Akhperjanian AG, Aye KM, Bazer-Bachi AR, Beilicke M, Benbow W, Berge D, Berghaus P, Bernlöhr K, Boisson C, Bolz O, Borrel V, Braun I, Breitling F, Brown AM, Bussons Gordo J, Chadwick PM, Chounet LM, Cornils R, Costamante L, Degrange B, Dickinson HJ, Djannati-Ataï A, Drury LO, Dubus G, Emmanoulopoulos D, Espigat P, Feinstein F, Fleury P, Fontaine G, Fuchs Y, Funk S, Gallant YA, Giebels B, Gillessen S, Glicenstein JF, Goret P, Hadjichristidis C, Hauser M, Heinzelmann G, Henri G, Hermann G, Hinton JA, Hofmann W, Holleran M, Horns D, Jacholkowska A, de Jager OC, Khélifi B, Komin N, Konopelko A, Latham IJ, Le Gallou R, Lemière A, Lemoine-Goumard M, Leroy N, Lohse T, Marcowith A, Martin JM, Martineau-Huynh O, Masterson C, McComb TJ, de Naurois M, Nolan SJ, Noutsos A, Orford KJ, Osborne JL, Ouchrif M, Panter M, Pelletier G, Pita S, Pühlhofer G, Punch M, Raubenheimer BC, Raue M, Raux J, Rayner SM, Reimer A, Reimer O, Ripken J, Rob L, Rolland L, Rowell G, Sahakian V, Saugé L, Schlenker S, Schlickeiser R, Schuster C, Schwanke U, Siewert M, Sol H, Spangler D, Steenkamp R, Stegmann C, Tavernet JP, Terrier R, Théoret CG, Tluczykont M, Vasileiadis G, Venter C, Vincent P, Völk HJ, and Wagner SJ

Abstract

X-ray binaries are composed of a normal star in orbit around a neutron star or stellar-mass black hole. Radio and x-ray observations have led to the presumption that some x-ray binaries called microquasars behave as scaled-down active galactic nuclei. Microquasars have resolved radio emission that is thought to arise from a relativistic outflow akin to active galactic nuclei jets, in which particles can be accelerated to large energies. Very high energy gamma-rays produced by the interactions of these particles have been observed from several active galactic nuclei. Using the High Energy Stereoscopic System, we find evidence for gamma-ray emission of >100 gigaelectron volts from a candidate microquasar, LS 5039, showing that particles are also accelerated to very high energies in these systems.

Published
2005
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