%0 Journal Article
%T Upper Limits from HESS active galactic nuclei Observations in 2005-2007
%+ Centre d'étude spatiale des rayonnements (CESR)
%+ Laboratoire Univers et Théories (LUTH (UMR_8102))
%+ Département d'Astrophysique, de physique des Particules, de physique Nucléaire et de l'Instrumentation Associée (DAPNIA)
%+ Laboratoire d'Astrophysique de Grenoble (LAOG)
%+ Laboratoire Leprince-Ringuet (LLR)
%+ Laboratoire d'Annecy de Physique des Particules (LAPP)
%+ APC - Astrophysique des Hautes Energies (APC - AHE)
%+ 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 Akhperjanian, A.G.
%A Barres de Almeida, U.
%A Bazer-Bachi, A.R.
%A Behera, B.
%A Beilicke, M.
%A Benbow, W.
%A Bernlohr, K.
%A Boisson, C.
%A Bolz, O.
%A Borrel, V.
%A Braun, I.
%A Brion, E.
%A Brown, A.M.
%A Buhler, R.
%A Bulik, T.
%A Busching, I.
%A Boutelier, T.
%A Carrigan, S.
%A Chadwick, P.M.
%A Chounet, L.-M.
%A Clapson, A.C.
%A Coignet, G.
%A Cornils, R.
%A Costamante, L.
%A Dalton, M.
%A Degrange, B.
%A Dickinson, H.J.
%A Djannati-Ataï, A.
%A Domainko, W.
%A Drury, L.O'C.
%A Dubois, F.
%A Dubus, G.
%A Dyks, J.
%A Egberts, K.
%A Emmanoulopoulos, D.
%A Espigat, P.
%A Farnier, C.
%A Feinstein, F.
%A Fiasson, A.
%A Forster, A.
%A Fontaine, G.
%A Funk, Seb.
%A Fusling, M.
%A Gallant, Y.A.
%A Giebels, B.
%A Glicenstein, J.F.
%A Gluck, B.
%A Goret, P.
%A Hadjichristidis, C.
%A Hauser, D.
%A Hauser, M.
%A Heinzelmann, G.
%A Henri, G.
%A Hermann, G.
%A Hinton, J.A.
%A Hoffmann, A.
%A Hofmann, W.
%A Holleran, M.
%A Hoppe, S.
%A Horns, D.
%A Jacholkowska, A.
%A de Jager, O.C.
%A Jung, I.
%A Katarzynski, K.
%A Kendziorra, E.
%A Kerschhaggl, M.
%A Khelifi, B.
%A Keogh, D.
%A Komin, Nu.
%A Kosack, K.
%A Lamanna, G.
%A Latham, I.J.
%A Lemiere, A.
%A Lemoine-Goumard, M.
%A Lenain, J.-P.
%A Lohse, T.
%A Martin, J.M.
%A Martineau-Huynh, O.
%A Marcowith, A.
%A Masterson, C.
%A Maurin, D.
%A Maurin, G.
%A Mccomb, T.J.L.
%A Moderski, R.
%A Moulin, Emmanuel
%A de Naurois, M.
%A Nedbal, D.
%A Nolan, S.J.
%A Ohm, S.
%A Olive, J.-P.
%A de Ona Wilhelmi, E.
%A Orford, K.J.
%A Osborne, J.L.
%A Ostrowski, M.
%A Panter, M.
%A Pedaletti, G.
%A Pelletier, G.
%A Petrucci, P.-O.
%A Pita, S.
%A Puhlhofer, G.
%A Punch, M.
%A Ranchon, S.
%A Raubenheimer, B.C.
%A Raue, M.
%A Rayner, S.M.
%A Renaud, M.
%A Ripken, J.
%A Rob, L.
%A Rolland, L.
%A Rosier-Lees, S.
%A Rowell, G.
%A Rudak, B.
%A Ruppel, J.
%A Sahakian, V.
%A Santangelo, A.
%A Schlickeiser, R.
%A Schock, F.
%A Schroder, R.
%A Schwanke, U.
%A Schwarzburg, S.
%A Schwemmer, S.
%A Shalchi, A.
%A Sol, H.
%A Spangler, D.
%A Stawarz, L.
%A Steenkamp, R.
%A Stegmann, C.
%A Superina, G.
%A Tam, P.H.
%A Tavernet, J.-P.
%A Terrier, R.
%A van Eldik, C.
%A Vasileiadis, G.
%A Venter, C.
%A Vialle, J.P.
%A Vincent, P.
%A Vivier, M.
%A Volk, H.J.
%A Volpe, F.
%A Wagner, S.J.
%A Ward, M.
%A Zdziarski, A.A.
%A Zech, A.
%Z 8 Pages, 2 Figures; Accepted on Nov 6, 2007 for publication in Astronomy & Astrophysics
%< avec comité de lecture
%Z PTA/07-057
%@ 0004-6361
%J Astronomy and Astrophysics - A&A
%I EDP Sciences
%V 478
%P 387-393
%8 2008
%D 2008
%Z 0711.3196
%R 10.1051/0004-6361:20078604
%Z Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO]
%Z Sciences of the Universe [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO]
%Z Sciences of the Universe [physics]/Astrophysics [astro-ph]Journal articles
%X AIMS: Very high energy (VHE; E>100 GeV) gamma-ray studies were performed for 18 active galactic nuclei (AGN) from a variety of AGN classes. METHODS: VHE observations of a sample of 14 AGN, considered candidate VHE emitters, were made with the High Energy Stereoscopic System (HESS) between January 2005 and July 2007. Large-zenith-angle observations of three northern AGN (Mkn 421, Mkn 501, 1ES 1218+304), known to emit VHE gamma rays, were also performed in order to sample their spectral energy distributions (SEDs) above 1 TeV. In addition, the VHE flux from 1ES 1101-232, previously detected by HESS in 2004-2005, was monitored during 2006 and 2007. RESULTS: As significant detections from the HESS observation program are reported elsewhere, the results reported here are primarily integral flux upper limits. The average exposure for each of the 14 VHE-candidate AGN is ~7 h live time, and the observations have an average energy threshold between 230 GeV and 590 GeV. Upper limits for these 14 AGN range from <0.9% to <4.9% of the Crab Nebula flux, and eight of these are the most constraining ever reported for the object. The brief (<2.2 h each) large-zenith-angle observations yield upper limits for Mkn 501 (<20% Crab above 2.5 TeV) and 1ES 1218+304 (<17% Crab above 1.0 TeV), and a marginal detection (3.5 sigma) of Mkn 421 (50% Crab above 2.1 TeV). 1ES 1101-232 was marginally detected (3.6 sigma, 1.7% Crab above 260 GeV) during the 2006 (13.7 h live time) observations, but not in the 2007 (4.6 h live time) data. The upper limit in 2007 (<1.9% Crab above 260 GeV) is below the average flux measured by HESS from 2004-2006.
%G English
%Z HESS
%L in2p3-00189509
%U https://hal.in2p3.fr/in2p3-00189509
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