Discovery of gamma-ray emission from the shell-type supernova remnant RCW 86 with H.E.S.S

F. Aharonian , A.G. Akhperjanian , U. Barres de Almeida , A.R. Bazer-Bachi (1) , B. Behera , M. Beilicke , W. Benbow , K. Bernlöhr , C. Boisson (2) , V. Borrel (1) , I. Braun , E. Brion (3) , J. Brucker , R. Bühler , T. Bulik , I. Büsching , T. Boutelier (4) , S. Carrigan , P.M. Chadwick , R. Chaves , L.-M. Chounet (5) , G. Coignet (6) , R. Cornils , L. Costamante , M. Dalton , B. Degrange (5) , H.J. Dickinson , A. Djannati-Ataï (7) , W. Domainko , L.O'C. Drury , F. Dubois (6) , G. Dubus (4) , J. Dyks , K. Egberts , D. Emmanoulopoulos , P. Espigat (8) , C. Farnier (9) , F. Feinstein (9) , A. Fiasson (3, 9) , A. Förster , G. Fontaine (5) , M. Füssling , S. Gabici , Y.A. Gallant (9) , L. Gérard (8) , B. Giebels (5) , J.F. Glicenstein (3) , B. Glück , P. Goret (3) , C. Hadjichristidis , D. Hauser , M. Hauser , G. Heinzelmann , G. Henri (4) , G. Hermann , J.A. Hinton , A. Hoffmann , W. Hofmann , M. Holleran , S. Hoppe , D. Horns , A. Jacholkowska (9) , O.C. de Jager , I. Jung , K. Katarzy'Nski , E. Kendziorra , M. Kerschhaggl , D. Khangulyan , B. Khélifi (5) , D. Keogh , Nu. Komin (9) , K. Kosack , G. Lamanna (6) , I.J. Latham , L. Lemoine-Goumard (10) , J.-P. Lenain (2) , T. Lohse , J.M. Martin (2) , O. Martineau-Huynh (11) , A. Marcowith (9) , C. Masterson , D. Maurin (11) , T.J.L. Mccomb , R. Moderski , Emmanuel Moulin (3) , M. Naumann-Godo (5) , M. de Naurois (11) , D. Nedbal , D. Nekrassov , S.J. Nolan , S. Ohm , J.-P. Olive (1) , E. de Oña Wilhelmi , K.J. Orford , J.L. Osborne , M. Ostrowski , M. Panter , G. Pedaletti , G. Pelletier (4) , P.-O. Petrucci (4) , S. Pita (8) , G. Pühlhofer , M. Punch (8) , A. Quirrenbach , B.C. Raubenheimer , M. Raue , S.M. Rayner , M. Renaud , F. Rieger , J. Ripken , L. Rob , S. Rosier-Lees (6) , G. Rowell , B. Rudak , J. Ruppel , V. Sahakian , A. Santangelo , R. Schlickeiser , F.M. Scöck , R. Schröder , U. Schwanke , S. Schwarzburg , S. Schwemmer , C. Stegmann , A. Shalchi , H. Sol (2) , D. Spangler , L. Stawarz , R. Steenkamp , G. Superina (5) , P.H. Tam , J.-P. Tavernet (11) , R. Terrier (8) , V. Marandon (8) , C. van Eldik , G. Vasileiadis (9) , C. Venter , J.P. Vialle (6) , P. Vincent (11) , M. Vivier (3) , H.J. Völk , F. Volpe (5) , S.J. Wagner , M. Ward , A.A. Zdziarski , A. Zech (2)

1 CESR - Centre d'étude spatiale des rayonnements
2 LUTH (UMR_8102) - Laboratoire Univers et Théories
3 IRFU - Institut de Recherches sur les lois Fondamentales de l'Univers
4 LAOG - Laboratoire d'Astrophysique de Grenoble
5 LLR - Laboratoire Leprince-Ringuet
6 LAPP - Laboratoire d'Annecy de Physique des Particules
7 APC - AHE - APC - Astrophysique des Hautes Energies
8 APC (UMR_7164) - AstroParticule et Cosmologie
9 LPTA - Laboratoire de Physique Théorique et Astroparticules
10 CENBG - Centre d'Etudes Nucléaires de Bordeaux Gradignan
11 LPNHE - Laboratoire de Physique Nucléaire et de Hautes Énergies

The shell-type supernova remnant (SNR) RCW 86, possibly associated with the historical supernova SN 185, with its relatively large size (about 40' in diameter) and the presence of non-thermal X-rays is a promising target for gamma-ray observations. The high sensitivity, good angular resolution of a few arc minutes and the large field of view of the High Energy Stereoscopic System (H.E.S.S.) make it ideally suited for the study of the gamma-ray morphology of such extended sources. H.E.S.S. observations have indeed led to the discovery of the SNR RCW 86 in very high energy (VHE; E > 100 GeV) gamma-rays. With 31 hours of observation time, the source is detected with a statistical significance of 8.5 sigma and is significantly more extended than the H.E.S.S. point spread function. Morphological studies have been performed and show that the gamma-ray flux does not correlate perfectly with the X-ray emission. The flux from the remnant is ~10% of the flux from the Crab nebula, with a similar photon index of about 2.5. Possible origins of the very high energy gamma-ray emission, via either Inverse Compton scattering by electrons or the decay of neutral pions produced by proton interactions, are discussed on the basis of spectral features obtained both in the X-ray and gamma-ray regimes.

Domaines: Cosmologie et astrophysique extra-galactique [astro-ph.CO]; Cosmologie et astrophysique extra-galactique [astro-ph.CO]; Astrophysique [astro-ph]

F. Aharonian, A.G. Akhperjanian, U. Barres de Almeida, A.R. Bazer-Bachi, B. Behera, et al.. Discovery of gamma-ray emission from the shell-type supernova remnant RCW 86 with H.E.S.S. The Astrophysical Journal, 2009, 692, pp.1500-1505. ⟨10.1088/0004-637X/692/2/1500⟩. ⟨in2p3-00331427⟩