Discovery of high and very high-energy emission from the BL Lacertae object SHBL J001355.9–185406

A. Abramowski , Fabio Acero (1) , F. Aharonian (2) , A. G. Akhperjanian , E. Angüner , G. Anton , S. Balenderan , Agnès Balzer , A. Barnacka , Y. Becherini (3, 4) , J. Becker Tjus , K. Bernlöhr (2) , E. Birsin , E. Bissaldi , J. Biteau (4) , C. Boisson , J. Bolmont (5) , P. Bordas , J. Brucker , F. Brun (2) , P. Brun (6) , T. Bulik , S. Carrigan , S. Casanova , M. Cerruti , P. M. Chadwick , R. Chalme-Calvet (5) , R. C. G. Chaves (6) , A. Cheesebrough , M. Chrétien (5) , S. Colafrancesco , G. Cologna , J. Conrad , C. Couturier (5) , M. Dalton (7) , M. K. Daniel , I. D. Davids , B. Degrange (4) , C. Deil , P. Dewilt , H. J. Dickinson , A. Djannati-Ataï (3) , W. Domainko , L. O’c. Drury , G. Dubus , K. Dutson , J. Dyks , M. Dyrda , T. Edwards , K. Egberts , P. Eger , P. Espigat (3) , C. Farnier , S. Fegan (4) , F. Feinstein (1) , M. V. Fernandes , D. Fernandez (1) , A. Fiasson (8) , G. Fontaine (4) , A. Förster , M. Füssling , M. Gajdus , Y. A. Gallant (1) , T. Garrigoux (5) , H. Gast , B. Giebels (4) , J. F. Glicenstein (6) , D. Göring , M.-H. Grondin , M. Grudzińska , S. Häffner , J. D. Hague , J. Hahn , J. Harris , G. Heinzelmann , G. Henri , G. Hermann , O. Hervet , A. Hillert , J. A. Hinton , W. Hofmann , P. Hofverberg , M. Holler , D. Horns , A. Jacholkowska (5) , C. Jahn , M. Jamrozy , M. Janiak , F. Jankowsky , I. Jung , M. A. Kastendieck , K. Katarzyński , U. Katz , S. Kaufmann , B. Khélifi (4) , Michel Kieffer (5) , S. Klepser , D. Klochkov , W. Kluźniak , T. Kneiske , D. Kolitzus , Nu. Komin (8) , K. Kosack (6) , S. Krakau , F. Krayzel (8) , P. P. Krüger , H. Laffon (4, 7) , G. Lamanna (8) , J. Lefaucheur (3) , M. Lemoine-Goumard (7) , J.-P. Lenain (5) , D. Lennarz , T. Lohse , A. Lopatin , C.-C. Lu , V. Marandon , A. Marcowith (1) , G. Maurin (8) , N. Maxted , M. Mayer , T. J. L. Mccomb , M. C. Medina (6) , J. Méhault (7) , U. Menzler , M. Meyer , R. Moderski , M. Mohamed , Emmanuel Moulin (6) , T. Murach , C. L. Naumann (5) , M. de Naurois (4) , D. Nedbal , J. Niemiec , S. J. Nolan , L. Oakes , S. Ohm , E. de Oña Wilhelmi , B. Opitz , M. Ostrowski , I. Oya , M. Panter , R. D. Parsons , M. Paz Arribas , N. W. Pekeur , G. Pelletier , J. Perez , P.-O. Petrucci , B. Peyaud (6) , S. Pita (3) , H. Poon , G. Pühlhofer , M. Punch (3) , A. Quirrenbach , S. Raab , M. Raue , A. Reimer , O. Reimer , M. Renaud (1) , R. de Los Reyes , F. Rieger , L. Rob , S. Rosier-Lees (8) , G. Rowell , B. Rudak , C. B. Rulten , V. Sahakian , D. A. Sanchez⋆ (2) , A. Santangelo , R. Schlickeiser , F. Schüssler (6) , A. Schulz , U. Schwanke , S. Schwarzburg , S. Schwemmer , H. Sol , G. Spengler , F. Spiess , Ł. Stawarz , R. Steenkamp , C. Stegmann , F. Stinzing , K. Stycz , I. Sushch , A. Szostek , J.-P. Tavernet (5) , R. Terrier (3) , M. Tluczykont , C. Trichard (8) , K. Valerius , C. van Eldik , G. Vasileiadis (1) , C. Venter , A. Viana (2) , P. Vincent (5) , H. J. Völk (2) , F. Volpe (2) , M. Vorster , S. J. Wagner , P. Wagner , M. Ward , M. Weidinger , R. White , A. Wierzcholska , P. Willmann , A. Wörnlein , D. Wouters (6) , M. Zacharias , A. Zajczyk (1) , A. A. Zdziarski , A. Zech , H.-S. Zechlin

1 LUPM - Laboratoire Univers et Particules de Montpellier
2 MPIK - Max-Planck-Institut für Kernphysik
3 APC (UMR_7164) - AstroParticule et Cosmologie
4 LLR - Laboratoire Leprince-Ringuet
5 LPNHE (UMR_7585) - Laboratoire de Physique Nucléaire et de Hautes Énergies
6 DAP - Département d'Astrophysique (ex SAP)
7 CENBG - Centre d'Etudes Nucléaires de Bordeaux Gradignan
8 LAPP - Laboratoire d'Annecy de Physique des Particules

The detection of the high-frequency peaked BL Lac object (HBL) SHBL J001355.9-185406 ($z$=0.095) at high (HE; 100 MeV$<$E$<$300 GeV) and very high-energy (VHE; $E>100\,{\rm GeV}$) with the \fer\ Large Area Telescope (LAT) and the High Energy Stereoscopic System (H.E.S.S.) is reported. Dedicated observations have been performed with the H.E.S.S. telescopes, leading to a detection at the $5.5\,\sigma$ significance level. The measured flux above 310 GeV is $(8.3 \pm 1.7_{\rm{stat}}\pm 1.7_{\rm{sys}})\times 10^{-13}$ photons \cms\ (about 0.6% of that of the Crab Nebula), and the power law spectrum has a photon index of \indexHESS. Using 3.5 years of publicly available \fla\ data, a faint counterpart has been detected in the LAT data at the $5.5\,\sigma$ significance level, with an integrated flux above 300 MeV of $(9.3 \pm 3.4_{\rm stat} \pm 0.8_{\rm sys})\times 10^{-10}$ photons \cms\ and a photon index of $\Gamma = 1.96 \pm 0.20_{\rm stat} \pm 0.08_{\rm sys}$. X-ray observations with \textit{Swift}-XRT allow the synchrotron peak energy in $\nu F_\nu$ representation to be located at $\sim 1.0\,{\rm keV}$. The broadband spectral energy distribution is modelled with a one-zone synchrotron self-Compton (SSC) model and the optical data by a black-body emission describing the thermal emission of the host galaxy. The derived parameters are typical for HBLs detected at VHE, with a particle dominated jet.

Keywords: gamma rays: general; BL Lacertae objects: individual: SHBL J001355.9-185406

Domains: High Energy Astrophysical Phenomena [astro-ph.HE]; High Energy Astrophysical Phenomena [astro-ph.HE]

A. Abramowski, Fabio Acero, F. Aharonian, A. G. Akhperjanian, E. Angüner, et al.. Discovery of high and very high-energy emission from the BL Lacertae object SHBL J001355.9–185406. Astronomy and Astrophysics - A&A, 2013, 554, pp.A72. ⟨10.1051/0004-6361/201220996⟩. ⟨cea-01135393⟩