Upper limits from HESS active galactic nuclei observations in 2005-2007

Aharonian F, Akhperjanian AG, De Almeida UB, Bazer-Bachi AR, Behera B, Beilicke M, Benbow W, Bernloehr K, Boisson C, Bolz O, Borrel V, Braun IV, Brion E, Brown AM, Buehler R, Bulik T, Buesching I, Boutelier T, Carrigan S, Chadwick PM, Chounet LM, Clapson AC, Coignet G, Cornils R, Costamante L, Dalton M, Degrange B, Dickinson HJ, Djannati-Ataie A, Domainko W, Drury LO, Dubois F, Dubus G, Dyks J, Egberts K, Emmanoulopoulos D, Espigat P, Farnier C, Feinstein F, Fiasson A, Foerster A, Fontaine G, Funk S, Fuessling M, Gallant YA, Giebels B, Glicenstein JF, Glueck B, Goret P, Hadjichristidis C, Hauser D, Hauser M, Heinzelmann G, Henri G, Hermann G, Hinton JA, Hoffmann A, Hofmann W, Holleran M, Hoppe S, Horns D, Jacholkowska A, De Jager OC, Jung I, Katarzynski K, Kendziorra E, Kerschhaggl M, Khelifi B, Keogh D, Komin N, Kosack K, Lamanna G, Latham IJ, Lemiere A, Lemoine-Goumard M, Lenain JP, Lohse T, Martin JM, Martineau-Huynh O, Marcowith A, Masterson C, Maurin D, Maurin G, Mccomb TJL, Moderski R, Moulin E, De Naurois M, Nedbal D, Nolan SJ, Ohm S, Olive JP, Wilhelmi EDO, Orford KJ, Osborne JL, Ostrowski M, Panter M, Pedaletti G, Pelletier G, Petrucci PO, Pita S, Puehlhofer G, Punch M, Ranchon S, Raubenheimer BC, Raue M, Rayner SM, Renaud M, Ripken J, Rob L, Rolland L, Rosier-Lees S, Rowell G, Rudak B, Ruppel J, Sahakian V, Santangelo A, Schlickeiser R, Schoeck F, Schroeck R, Schwanke U, Schwarzburg S, Schwemmer S, Shalchi A, Sol H, Spangler D, Stawarz L, Steenkamp R, Stegmann C, Superina G, Tam PH, Tavernet JP, Terrier R, van Eldik C, Vasileiadis G, Venter C, Vialle JP, Vincent P, Vivier M, Voelk HJ, Volpe F, Wagner SJ, Ward M, Zdziarski AA, Zech A (2008)

Publication Status: Published

Publication Type: Journal article, Original article

Publication year: 2008

Journal

Publisher: EDP Sciences

Book Volume: 478

Pages Range: 387-393

Journal Issue: 2

DOI: 10.1051/0004-6361:20078604

Abstract

Aims: Very high energy (VHE; E > 100 GeV) γ-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 γ-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 (3.5σ) of Mkn 421 (50% Crab above 2.1 TeV). 1ES 1101-232 was marginally detected (3.6σ, 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. © ESO 2008.

Authors with CRIS profile

Involved external institutions

Max-Planck-Institut für Kernphysik (MPIK) / Max Planck Institute for Nuclear Physics Germany (DE) University of Montpellier / Université Montpellier France (FR) Durham University United Kingdom (GB) Université Joseph Fourier (UJF Grenoble 1) France (FR) École Polytechnique - Université Paris-Saclay France (FR) Laboratoire d'Annecy le Vieux de Physique des Particules France (FR) Nicolaus Copernicus Astronomical Centre of the Polish Academy of Sciences Poland (PL) French Alternative Energies and Atomic Energy Commission (CEA) France (FR) University of Paris 6 - Pierre et Marie Curie / Université Paris VI Pierre et Marie Curie (UPMC) France (FR) Univerzita Karlova v Praze / Charles University in Prague Czech Republic (CZ) University of Namibia (UNAM) Namibia (NA) Ruprecht-Karls-Universität Heidelberg Germany (DE) Universität Hamburg (UHH) Germany (DE) Humboldt-Universität zu Berlin Germany (DE) University of Paris 7 - Denis Diderot / Université Paris VII Denis Diderot France (FR) Yerevan Physics Institute (YerPhI) / Երևանի Ֆիզիկայի Ինստիտուտ Armenia (AM) Eberhard Karls Universität Tübingen Germany (DE) Dublin Institute for Advanced Studies (DIAS) Ireland (IE) University of Leeds United Kingdom (GB) Ruhr-Universität Bochum (RUB) Germany (DE) Noordwes-Universiteit / North-West University South Africa (ZA) Université Toulouse III - Paul Sabatier France (FR) University of Adelaide Australia (AU) Nicolaus Copernicus University (NCU) / Uniwersytet Mikołaja Kopernika w Toruniu (UMK) Poland (PL) Jagiellonian University / Uniwersytet Jagielloński (UJ) Poland (PL)

How to cite

APA:

Aharonian, F., Akhperjanian, A.G., De Almeida, U.B., Bazer-Bachi, A.R., Behera, B., Beilicke, M.,... Zech, A. (2008). Upper limits from HESS active galactic nuclei observations in 2005-2007. Astronomy & Astrophysics, 478(2), 387-393. https://dx.doi.org/10.1051/0004-6361:20078604

MLA:

Aharonian, F., et al. "Upper limits from HESS active galactic nuclei observations in 2005-2007." Astronomy & Astrophysics 478.2 (2008): 387-393.

BibTeX: Download