155 articles – 1965 Notices  [english version]
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Astronomy and Astrophysics 470 (2007) 475-489
Detection of VHE gamma-ray emission from the distant blazar 1ES 1101-232 with H.E.S.S. and broadband characterisation
F. Aharonian, A. G. Akhperjanian, A.R. Bazer-Bachi1, M. Beilicke, W. Benbow, D. Berge, K. Bernlöhr, C. Boisson2, O. Bolz, V. Borrel1, I. Braun, E. Brion3, A. M. Brown, R. Buhler, I. Busching, T. Boutelier, S. Carrigan, P. M. Chadwick, L.M. Chounet4, G. Coignet5, R. Cornils, L. Costamante, B. Degrange4, H. J. Dickinson, A. Djannati-Ataï6, L. O'Connor-Drury, G. Dubus4, K. Egberts, D. Emmanoulopoulos, P. Espigat6, C. Farnier7, F. Feinstein7, E. Ferrero, A. Fiasson7, G. Fontaine4, S. Funk, M. Fuling, Y. A. Gallant7, B. Giebels4, J.F. Glicenstein3, B. Glück, P. Goret3, C. Hadjichristidis, D. Hauser, M. Hauser, G. Heinzelmann, G. Henri, G. Hermann, J. A. Hinton, A. Hoffmann, W. Hofmann, M. Holleran, S. Hoppe, D. Horns, A. Jacholkowska7, O. C. De Jager, E. Kendziorra, M. Kerschhaggl, B. Khelifi4, N. Komin7, K. Kosack, G. Lamanna5, I. J. Latham, R. Le Gallou, A. Lemiere6, M. Lemoine-Goumard4, T. Lohse, J.M. Martin2, O. Martineau-Huynh8, A. Marcowith1, 7, C. Masterson, G. Maurin6, T. J. L. Mccomb, E. Moulin3, 7, M. De Naurois8, D. Nedbal, S. J. Nolan, A. Noutsos, J.P. Olive1, K. J. Orford, J. L. Osborne, M. Panter, G. Pelletier, P.O. Petrucci9, S. Pita6, G. Pühlhofer, M. Punch6, S. Ranchon5, B. C. Raubenheimer, M. Raue, S. M. Rayner, A. Reimer, O. Reimer, J. Ripken, L. Rob, L. Rolland3, S. Rosier-Lees5, G. Rowell, V. V. Sahakian, A. Santangelo, L. Sauge9, S. Schlenker, R. Schlickeiser, R. Schröder, U. Schwanke, S. Schwarzburg, S. Schwemmer, A. Shalchi, H. Sol2, D. Spangler, F. Spanier, R. Steenkamp, C. Stegmann, G. Superina4, P. H. Tam, J.P. Tavernet8, R. Terrier6, M. Tluczykont4, C. Van Eldik, G. Vasileiadis7, C. Venter, J.P. Vialle5, P. Vincent8, H. J. Völk, S. J. Wagner, M. Ward
HESS Collaboration(s)

The blazar 1ES 1101-232 was observed with the High Energy Stereoscopic System (H.E.S.S.) of Atmospheric Cherenkov Telescopes (ACT) in 2004 and 2005, for a live time of 43 hours. VHE (E > 10^11 eV) gamma-rays were detected for the first time from this object. VHE observations of blazars are used to investigate the inner parts of the blazar jets, and also to study the extragalactic background light (EBL) in the near-infrared band. Observations in 2005 were conducted in a multiwavelength campaign, together with the RXTE satellite and optical observations. In 2004, simultaneous observations with XMM-Newton were obtained. 1ES 1101-232 was detected with H.E.S.S. with an excess of 722 photons, at a significance of 12 sigma. The measured VHE gamma-ray flux amounts to dN/dE = (5.63 +- 0.89) x 10^-13 (E/TeV)^-(2.94 +- 0.20) cm^-2 s^-1 TeV^-1, above a spectral energy threshold of 225 GeV. No significant variation of the VHE gamma-ray flux on any time scale was found. 1ES 1101-232 exhibits a very hard spectrum, and at a redshift of z=0.186, is the blazar with the highest confirmed redshift detected in VHE gamma-rays so far. The data allow the construction of truly simultaneous spectral energy distributions of the source, from the optical to the VHE band. Using an EBL model with \nu F_\nu = 14 nW m^-2 sr^-1 at 1.5 \mu m as presented in Aharonian et al. (Nature, 2006, 440, 1018) suggests an intrinsic VHE power output peak of the source at above 3 TeV.
1 :  CESR - Centre d'étude spatiale des rayonnements
2 :  LUTH - Laboratoire Univers et Théories
3 :  DAPNIA - Département d'Astrophysique, de physique des Particules, de physique Nucléaire et de l'Instrumentation Associée
4 :  LLR - Laboratoire Leprince-Ringuet
5 :  LAPP - Laboratoire d'Annecy le Vieux de Physique des Particules
6 :  APC - UMR 7164 - AstroParticule et Cosmologie
7 :  LPTA - Laboratoire de Physique Théorique et Astroparticules
8 :  LPNHE - Laboratoire de Physique Nucléaire et de Hautes Énergies
9 :  LAOG - Laboratoire d'Astrophysique de Grenoble
Physique/Astrophysique/Cosmologie et astrophysique extra-galactique

Planète et Univers/Astrophysique/Cosmologie et astrophysique extra-galactique

Planète et Univers/Astrophysique
gamma rays: observations – galaxies: active – BL Lacertae objects: individual (1ES 1101-232)
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