H.E.S.S. upper limits for Kepler's supernova remnant

F. Aharonian , A.G. Akhperjanian , U. Barres de Almeida , A.R. Bazer-Bachi (1) , B. Behera , M. Beilicke , W. Benbow , D. Berge , K. Bernl¨ohr , C. Boisson (2) , O. Bolz , V. Borrel (1) , I. Braun , E. Brion (3) , J. Brucker , R. B¨uhler , T. Bulik , I. B¨usching , T. Boutelier (4) , S. Carrigan , P.M. Chadwick , L.-M. Chounet (5) , A.C. Clapson , 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 (9) , A. Förster , G. Fontaine (5) , M. Füssling , Y.A. Gallant (9) , 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. Katarzynski , E. Kendziorra , M. Kerschhaggl , B. Khélifi (5) , D. Keogh , Nu. Komin (9) , K. Kosack , G. Lamanna (6) , I.J. Latham , M. Lemoine-Goumard (5, 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 Ona Wilhelmi (8) , 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 , J. Ripken , L. Rob , S. Rosier-Lees (6) , G. Rowell , B. Rudak , J. Ruppel , V. Sahakian , A. Santangelo , R. Schlickeiser , F.M. Schöck , R. Schröder , U. Schwanke , S. Schwarzburg , S. Schwemmer , A. Shalchi , H. Sol (2) , D. Spangler , Ł. Stawarz , R. Steenkamp , C. Stegmann , G. Superina (5) , P.H. Tam , J.-P. Tavernet (11) , R. Terrier (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

Observations of Kepler's supernova remnant (G4.5+6.8) with the H.E.S.S. telescope array in 2004 and 2005 with a total live time of 13 h are presented. Stereoscopic imaging of Cherenkov radiation from extensive air showers is used to reconstruct the energy and direction of the incident gamma rays. No evidence for a very high energy (VHE: >100 GeV) gamma-ray signal from the direction of the remnant is found. An upper limit (99% confidence level) on the energy flux in the range 230 GeV - 12.8 TeV of 8.6 x 10^{-13} erg cm^{-2} s^{-1} is obtained. In the context of an existing theoretical model for the remnant, the lack of a detectable gamma-ray flux implies a distance of at least 6.4 kpc. A corresponding upper limit for the density of the ambient matter of 0.7 cm^{-3} is derived. With this distance limit, and assuming a spectral index Gamma = 2, the total energy in accelerated protons is limited to E_p < 8.6 x 10^{49} erg. In the synchrotron/inverse Compton framework, extrapolating the power law measured by RXTE between 10 and 20 keV down in energy, the predicted gamma-ray flux from inverse Compton scattering is below the measured upper limit for magnetic field values greater than 52 muG.

Mots clés: SN1604; G4.5+6.8); gamma rays: observations; ISM: supernova remnants; ISM: individual objects: (Kepler's SNR

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.. H.E.S.S. upper limits for Kepler's supernova remnant. Astronomy and Astrophysics - A&A, 2008, 488, pp.219-223. ⟨10.1051/0004-6361:200809401⟩. ⟨in2p3-00289653⟩