Please use this identifier to cite or link to this item:
Title: HESS observations and VLT spectroscopy of PG1553+113
Authors: Aharonian, F.
Benbow, W.
Bernlöhr, K.
Bolz, O.
Braun, I.
Bühler, R.
Carrigan, S.
Clapson, A. C.
Costamante, L.
Domainko, W.
Egberts, K.
Ruppel, J.
Lemière, A.
Maurin, G.
De Oña Wilhelmi E
Pita, S.
Punch, M.
Terrier, R.
Aharonian, F.
Drury, L. O.
Schöck, F.
Glicenstein, J. F.
Masterson, C.
Behera, B.
Schlickeiser, R.
Fiasson, A.
Emmanoulopoulos, D.
Hauser, M.
Pedaletti, G.
Pühlhofer, G.
Schwemmer, S.
Gallant, Y. A.
Moderski, R.
Stegmann, C.
Jacholkowska, A.
Komin, N.
Marcowith, A.
Schröder, R.
Vasileiadis, G.
Boutelier, T.
Dubus, G.
Henri, G.
Pelletier, G.
Rudak, B.
Shalchi, A.
Völk, H. J.
Petrucci, P. -. O.
Hoffmann, A.
Hauser, D.
Horns, D.
Kendziorra, E.
Santangelo, A.
Schwarzburg, S.
Martineau-Huynh, O.
Zdziarski, A. A.
Maurin, D.
De Naurois M
Akhperjanian, A. G.
Steenkamp, R.
Tavernet, J. -. P.
Vincent, P.
Nedbal, D.
Hermann, G.
Rob, L.
Ostrowski, M.
Hinton, J. A.
Stawarz, Ł.
Bulik, T.
Dyks, J.
Sahakian, V.
Hofmann, W.
Rowell, G.
Katarzyński, K.
Costamante, L.
Djannati-Ataï, A.
Bazer-Bachi, A. R.
Tam, P. H.
Espigat, P.
Lemière, A.
Goret, P.
Hoppe, S.
Maurin, G.
De Oña Wilhelmi E
Pita, S.
Punch, M.
Terrier, R.
Kosack, K.
Keogh, D.
Borrei, V.
Ohm, S.
Panter, M.
Renaud, M.
Moulin, E.
Van Eldik C
Olive, J. -. P.
Beilicke, M.
Cornils, R.
Heinzelmann, G.
Latham, I. J.
Rolland, L.
Volpe, F.
Raue, M.
Ripken, J.
Bernlöhr, K.
Dalton, M.
Funk, S.
Füßling, M.
Kerschhaggl, M.
Lohse, T.
McComb, T. J. L.
Schwanke, U.
Boisson, C.
Coignet, G.
Vivier, M.
Lenain, J. -. P.
Martin, J. M.
Sol, H.
Zech, A.
Brion, E.
De Barres Almeida U
Nolan, S. J.
Brown, A. M.
Chadwick, P. M.
Dickinson, H. J.
Dubois, F.
Hadjichristidis, C.
Orford, K. J.
Osborne, J. L.
Rayner, S. M.
Spangler, D.
Lamanna, G.
Förster, A.
Ward, M.
Büsching, I.
Wagner, S. J.
Holleran, M.
De Jager OC
Raubenheimer, B. C.
Venter, C.
Chounet, L. -. M.
Degrange, B.
Fontaine, G.
Glück, B.
Ranchon, S.
Giebels, B.
Khélifi, B.
Lemoine-Goumard, M.
Farnier, C.
Superina, G.
Rosier-Lees, S.
Vialle, J. P.
Djannati-Ataï, A.
Espigat, P.
Jung, I.
Feinstein, F.
First Published: Jan-2008
Publisher: EDP Sciences for European Southern Observatory (ESO)
Citation: Astronomy & Astrophysics, 2008, 477 (2), pp. 481-489
Abstract: Aims.The properties of the very high energy (VHE; E > 100 GeV) $\gamma$-ray emission from the high-frequency peaked BL Lac PG 1553+113 are investigated. An attempt is made to measure the currently unknown redshift of this object. Methods.VHE Observations of PG 1553+113 were made with the High Energy Stereoscopic System (HESS) in 2005 and 2006. H + K (1.45-2.45 $\mu$m) spectroscopy of PG 1553+113 was performed in March 2006 with SINFONI, an integral field spectrometer of the ESO Very Large Telescope (VLT) in Chile. Results.A VHE signal, ~10 standard deviations, is detected by HESS during the 2 years of observations (24.8 h live time). The integral flux above 300 GeV is $(4.6 \pm 0.6_{\rm stat} \pm 0.9_{\rm syst})$ $\times$ 10-12 cm-2 s-1, corresponding to ~3.4% of the flux from the Crab Nebula above the same threshold. The time-averaged energy spectrum is measured from 225 GeV to ~1.3 TeV, and is characterized by a very soft power law (photon index of $\Gamma = 4.5 \pm 0.3_{\rm stat} \pm 0.1_{\rm syst}$). No evidence for any flux or spectral variations is found on any sampled time scale within the VHE data. The redshift of PG 1553+113 could not be determined. Indeed, even though the measured SINFONI spectrum is the most sensitive ever reported for this object at near infrared wavelengths, and the sensitivity is comparable to the best spectroscopy at other wavelengths, no absorption or emission lines were found in the H+K spectrum presented here.
DOI Link: 10.1051/0004-6361:20078603
ISSN: 0004-6361
eISSN: 1432-0746
Version: Publisher Version
Status: Peer-reviewed
Type: Journal Article
Rights: Copyright © 2008 ESO. Reproduced with permission from Astronomy & Astrophysics, © ESO.
Appears in Collections:Published Articles, Dept. of Physics and Astronomy

Files in This Item:
File Description SizeFormat 
aa8603-07.pdfPublished (publisher PDF)318.9 kBAdobe PDFView/Open

Items in LRA are protected by copyright, with all rights reserved, unless otherwise indicated.