%0 Journal Article
%T Observations of Selected AGN with HESS
%+ Laboratoire Leprince-Ringuet (LLR)
%+ AstroParticule et Cosmologie (APC (UMR_7164))
%+ Laboratoire de Physique Théorique et Astroparticules (LPTA)
%+ Laboratoire de Physique Nucléaire et de Hautes Énergies (LPNHE)
%A Aharonian, F.
%A G. Akhperjanian, A.
%A R. Bazer-Bachi, A.
%A Beilicke, M.
%A Benbow, W.
%A Berge, D.
%A Bernlöhr, K.
%A Boisson, C.
%A Bolz, O.
%A Borrel, V.
%A Braun, I.
%A Breitling, F.
%A M. Brown, A.
%A M. Chadwick, P.
%A Chounet, L.-M.
%A Cornils, R.
%A Costamante, L.
%A Degrange, B.
%A Dickinson, H.J.
%A Djannati-Ataï, A.
%A L. O'C., Drury
%A Dubus, G.
%A Emmanoulopoulos, D.
%A Espigat, P.
%A Feinstein, F.
%A Fontaine, G.
%A Fuchs, Y.
%A Funk, S.
%A Gallant, Y.A.
%A Giebels, B.
%A Gillessen, S.
%A Glicenstein, J.F.
%A Goret, P.
%A Hadjichristidis, C.
%A Hauser, M.
%A Heinzelmann, G.
%A Henri, G.
%A Hermann, G.
%A A. Hinton, J.
%A Hofmann, W.
%A Holleran, M.
%A Horns, D.
%A Jacholkowska, A.
%A Dejager, O.C.
%A Khélifi, B.
%A Komin, Nu.
%A Konopelko, A.
%A J. Latham, I.
%A Le Gallou, R.
%A Lemière, A.
%A Lemoine-Goumard, M.
%A Leroy, N.
%A Lohse, T.
%A Martin, J.M.
%A Martineau-Huynh, O.
%A Marcowith, A.
%A Masterson, C.
%A J. L. Mccomb, T.
%A de Naurois, M.
%A J. Nolan, S.
%A Noutsos, A.
%A J. Orford, K.
%A L. Osborne, J.
%A Ouchrif, M.
%A Panter, M.
%A Pelletier, G.
%A Pita, S.
%A Pühlhofer, G.
%A Punch, M.
%A C. Raubenheimer, B.
%A Raue, M.
%A Raux, J.
%A M. Rayner, S.
%A Reimer, A.
%A Reimer, O.
%A Ripken, J.
%A Rob, L.
%A Rolland, L.
%A Rowell, G.
%A Sahakian, V.
%A Saugé, L.
%A Schlenker, S.
%A Schlickeiser, R.
%A Schuster, C.
%A Schwanke, U.
%A Siewert, M.
%A Sol, H.
%A Spangler, D.
%A Steenkamp, R.
%A Stegmann, C.
%A Tavernet, J.-P.
%A Terrier, R.
%A Théoret, C.G.
%A Tluczykont, M.
%A Vasileiadis, G.
%A Venter, C.
%A Vincent, P.
%A J. Völk, H.
%A J. Wagner, S.
%< avec comité de lecture
%Z APC-05-41
%@ 0004-6361
%J Astronomy and Astrophysics - A&A
%I EDP Sciences
%V 441
%P 465-472
%8 2005
%D 2005
%Z astro-ph/0507207
%R 10.1051/0004-6361:20053478
%K Galaxies: active
%K BL Lacertae objects: Individual
%K Gamma rays: observations
%Z Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO]
%Z Sciences of the Universe [physics]/Astrophysics [astro-ph]Journal articles
%X A sample of selected active galactic nuclei (AGN) was observed in 2003 and 2004 with the High Energy Stereoscopic System (H.E.S.S.), an array of imaging atmospheric-Cherenkov telescopes in Namibia. The redshifts of these candidate very-high-energy (VHE, >100 GeV) gamma-ray emitters range from z=0.00183 to z=0.333. Significant detections were already reported for some of these objects, such as PKS 2155-304 and Markarian 421. Marginal evidence (3.1 sigma) for a signal is found from large-zenith-angle observations of Markarian 501, corresponding to an integral flux of I(>1.65 TeV) = (1.5 +/- 0.6 (stat) +/- 0.3 (syst)) x 10^{-12} cm^{-2} s^{-1} or ~15% of the Crab Nebula flux. Integral flux upper limits for 19 other AGN, based on exposures of ~1 to ~8 hrs live time, and with average energy thresholds between 160 GeV and 610 GeV, range from 0.4% to 5.1% of the Crab Nebula flux. All the upper limits are the most constraining ever reported for these objects.
%G English
%Z HESS
%L in2p3-00024534
%U https://hal.in2p3.fr/in2p3-00024534
%~ IN2P3
%~ OBSPM
%~ CEA
%~ UNIV-PARIS7
%~ X
%~ UPMC
%~ LPTA
%~ LLR
%~ LPNHE
%~ APC
%~ CNRS
%~ UNIV-MONTP2
%~ X-LLR
%~ X-DEP
%~ X-DEP-PHYS
%~ DSM-IRFU
%~ IRFU-APC
%~ PSL
%~ UPMC_POLE_2
%~ UNIV-MONTPELLIER
%~ CEA-DRF
%~ SORBONNE-UNIVERSITE
%~ SU-SCIENCES
%~ UNIV-PARIS
%~ UP-SCIENCES
%~ OBSPM-PSL
%~ SU-TI
%~ ALLIANCE-SU
%~ UM1-UM2
%~ LPNHE-2