Measurement of the EBL spectral energy distribution using the VHE $\gamma$-ray spectra of H.E.S.S. blazars

H. Abdalla , A. Abramowski , F. Aharonian , F. Ait Benkhali , E.O. Angüner , M. Arrieta (1) , P. Aubert (2) , M. Backes , A. Balzer , M. Barnard , Y. Becherini , J. Becker Tjus , D. Berge , S. Bernhard , K. Bernlöhr , R. Blackwell , M. Böttcher , C. Boisson (1) , J. Bolmont (3) , P. Bordas , J. Bregeon (4) , F. Brun (5) , P. Brun (6) , M. Bryan , T. Bulik , M. Capasso , J. Carr (7) , S. Casanova , M. Cerruti (3) , N. Chakraborty , R. Chalme-Calvet (3) , R.C.G. Chaves (4) , A. Chen , J. Chevalier (2) , M. Chrétien (3) , S. Colafrancesco , G. Cologna , B. Condon (5) , J. Conrad , Y. Cui , I.D. Davids , J. Decock (6) , B. Degrange (8) , C. Deil , J. Devin (4) , P. Dewilt , L. Dirson , A. Djannati-Atai (9) , W. Domainko , A. Donath , L.O'C. Drury , G. Dubus (10) , K. Dutson , J. Dyks , T. Edwards , K. Egberts , P. Eger , J.-P. Ernenwein (7) , S. Eschbach , C. Farnier , S. Fegan (8) , M.V. Fernandes , A. Fiasson (2) , G. Fontaine (8) , A. Förster , S. Funk , M. Füssling , S. Gabici (9) , M. Gajdus , Y.A. Gallant (4) , T. Garrigoux , G. Giavitto , B. Giebels (8) , J.F. Glicenstein (6) , D. Gottschall , A. Goyal , M.-H. Grondin (5) , D. Hadasch , J. Hahn , M. Haupt , J. Hawkes , G. Heinzelmann , G. Henri (10) , G. Hermann , O. Hervet (1) , J.A. Hinton , W. Hofmann , C. Hoischen , M. Holler (8) , D. Horns , A. Ivascenko , A. Jacholkowska (3) , M. Jamrozy , M. Janiak , D. Jankowsky , F. Jankowsky , M. Jingo , T. Jogler , L. Jouvin (9) , I. Jung-Richardt , M.A. Kastendieck , K. Katarzyński , U. Katz , D. Kerszberg (3) , B. Khélifi (9) , M. Kieffer (3) , J. King , S. Klepser , D. Klochkov , W. Kluźniak , D. Kolitzus , Nu. Komin , K. Kosack (6) , S. Krakau , M. Kraus , F. Krayzel (2) , P.P. Krüger , H. Laffon (5) , G. Lamanna (2) , J. Lau , J.-P. Lees (2) , J. Lefaucheur (1) , V. Lefranc (6) , A. Lemière (9) , M. Lemoine-Goumard (5) , J.-P. Lenain (3) , E. Leser , T. Lohse , M. Lorentz (6) , R. Liu , R. López-Coto , I. Lypova , V. Marandon , Alexandre Marcowith (4) , C. Mariaud (8) , R. Marx , G. Maurin (2) , N. Maxted , M. Mayer , P.J. Meintjes , M. Meyer , A.M.W. Mitchell , R. Moderski , M. Mohamed , L. Mohrmann , E. Moulin (6) , T. Murach , M. de Naurois (8) , F. Niederwanger , J. Niemiec , L. Oakes , P. O'Brien , H. Odaka , S. Öttl , S. Ohm , M. Ostrowski , I. Oya , M. Padovani (4) , M. Panter , R.D. Parsons , N.W. Pekeur , G. Pelletier (10) , C. Perennes (3) , P.-O. Petrucci (10) , B. Peyaud (6) , Q. Piel (2) , S. Pita (9) , H. Poon , D. Prokhorov , H. Prokoph , G. Pühlhofer , M. Punch (9) , A. Quirrenbach , S. Raab , A. Reimer , O. Reimer , Matthieu Renaud (4) , R. de Los Reyes , F. Rieger , C. Romoli , S. Rosier-Lees (2) , G. Rowell , B. Rudak , C.B. Rulten (1) , V. Sahakian , D. Salek , D.A. Sanchez (2) , A. Santangelo , M. Sasaki , R. Schlickeiser , F. Schüssler (6) , A. Schulz , U. Schwanke , S. Schwemmer , M. Settimo (3) , A.S. Seyffert , N. Shafi , I. Shilon , R. Simoni , H. Sol (1) , F. Spanier , G. Spengler , F. Spies , R. Steenkamp , C. Stegmann , I. Sushch , J.-P. Tavernet (3) , T. Tavernier (9) , A.M. Taylor , R. Terrier (9) , L. Tibaldo , D. Tiziani , M. Tluczykont , C. Trichard (7) , R. Tuffs , Y. Uchiyama , D.J. van Der Walt , C. van Eldik , C. van Rensburg , B. van Soelen , George Vasileiadis (4) , J. Veh , C. Venter , A. Viana , P. Vincent (3) , J. Vink , F. Voisin , H.J. Völk , T. Vuillaume (2) , Z. Wadiasingh , S.J. Wagner , P. Wagner , R.M. Wagner , R. White , A. Wierzcholska , P. Willmann , A. Wörnlein , D. Wouters (6) , R. Yang , V. Zabalza , D. Zaborov (8) , M. Zacharias , A.A. Zdziarski , A. Zech (1) , F. Zefi (8) , A. Ziegler , N. Zywucka , F. Jankowski , E.F. Keane , E. Petroff

1 LUTH (UMR_8102) - Laboratoire Univers et Théories
2 LAPP - Laboratoire d'Annecy de Physique des Particules
3 LPNHE (UMR_7585) - Laboratoire de Physique Nucléaire et de Hautes Énergies
4 LUPM - Laboratoire Univers et Particules de Montpellier
5 CENBG - Centre d'Etudes Nucléaires de Bordeaux Gradignan
6 IRFU - Institut de Recherches sur les lois Fondamentales de l'Univers
7 CPPM - Centre de Physique des Particules de Marseille
8 LLR - Laboratoire Leprince-Ringuet
9 APC (UMR_7164) - AstroParticule et Cosmologie
10 IPAG - Institut de Planétologie et d'Astrophysique de Grenoble

Very high-energy γ rays (VHE, E ≳ 100 GeV) propagating over cosmological distances can interact with the low-energy photons of the extragalactic background light (EBL) and produce electron-positron pairs. The transparency of the Universe to VHE γ rays is then directly related to the spectral energy distribution (SED) of the EBL. The observation of features in the VHE energy spectra of extragalactic sources allows the EBL to be measured, which otherwise is very difficult. An EBL model-independent measurement of the EBL SED with the H.E.S.S. array of Cherenkov telescopes is presented. It was obtained by extracting the EBL absorption signal from the reanalysis of high-quality spectra of blazars. From H.E.S.S. data alone the EBL signature is detected at a significance of 9.5σ, and the intensity of the EBL obtained in different spectral bands is presented together with the associated γ-ray horizon. Key words: gamma rays: galaxies / BL Lacertae objects: general / cosmic background radiation / infrared: diffuse background† Deceased.⋆ Corresponding authors: H.E.S.S. Collaboration, e-mail: [e-mail]

Mots clés: Gamma rays: galaxies — Cosmology: cosmic background radiation Send offprint requests to: HESS collaboration; gamma rays: galaxies; BL Lacertae objects: general; cosmic background radiation; infrared: diffuse background; gamma ray: VHE; blazar: spectrum; spectral; HESS; electron positron; Cherenkov counter; energy spectrum; transparency; absorption; background; signature; horizon; photon; propagation

Domaines: Astrophysique [astro-ph]

H. Abdalla, A. Abramowski, F. Aharonian, F. Ait Benkhali, E.O. Angüner, et al.. Measurement of the EBL spectral energy distribution using the VHE $\gamma$-ray spectra of H.E.S.S. blazars. Astronomy and Astrophysics - A&A, 2017, 606, pp.A59. ⟨10.1051/0004-6361/201731200⟩. ⟨hal-01645741⟩