H.E.S.S. observations of the Carina nebula and its enigmatic colliding wind binary Eta Carinae
Creators: name: HESS Collaboration
name: Abramowski, A.
name: Acero, F.
name: Aharonian, F.
name: Akhperjanian, A. G.
name: Anton, G.
name: Balzer, A.
name: Barnacka, A.
name: Becherini, Y.
name: Becker, J.
name: Bernlöhr, K.
name: Birsin, E.
name: Biteau, J.
name: Bochow, A.
name: Boisson, C.
name: Bolmont, J.
name: Bordas, P.
name: Brucker, J.
name: Brun, F.
name: Brun, P.
name: Bulik, T.
name: Büsching, I.
name: Carrigan, S.
name: Casanova, S.
name: Cerruti, M.
name: Chadwick, P. M.
name: Charbonnier, A.
name: Chaves, R. C. G.
name: Cheesebrough, A.
name: Cologna, G.
name: Conrad, J.
name: Dalton, M.
name: Daniel, M. K.
name: Davids, I. D.
name: Degrange, B.
name: Deil, C.
name: Dickinson, H. J.
name: Djannati-Ataï, A.
name: Domainko, W.
name: Drury, L. O'C.
name: Dubus, G.
name: Dutson, K.
name: Dyks, J.
name: Dyrda, M.
name: Egberts, K.
name: Eger, P.
name: Espigat, P.
name: Fallon, L.
name: Fegan, S.
name: Feinstein, F.
name: Fernandes, M. V.
name: Fiasson, A.
name: Fontaine, G.
name: Förster, A.
name: Füßling, M.
name: Gallant, Y. A.
name: Garrigoux, T.
name: Gast, H.
name: Gèrard, L.
name: Giebels, B.
name: Glicenstein, J. F.
name: Glück, B.
name: Göring, D.
name: Grondin, M. -H.
name: Häffner, S.
name: Hague, J. D.
name: Hahn, J.
name: Hampf, D.
name: Harris, J.
name: Hauser, M.
name: Heinz, S.
name: Heinzelmann, G.
name: Henri, G.
name: Hermann, G.
name: Hillert, A.
name: Hinton, J. A.
name: Hofmann, W.
name: Hofverberg, P.
name: Holler, M.
name: Horns, D.
name: Jacholkowska, A.
name: Jahn, C.
name: Jamrozy, M.
name: Jung, I.
name: Kastendieck, M. A.
name: Katarzyński, K.
name: Katz, U.
name: Kaufmann, S.
name: Khélifi, B.
name: Klochkov, D.
name: Kluźniak, W.
name: Kneiske, T.
name: Komin, Nu.
name: Kosack, K.
name: Kossakowski, R.
name: Krayzel, F.
name: Laffon, H.
name: Lamanna, G.
name: Lenain, J. -P.
name: Lennarz, D.
name: Lohse, T.
name: Lopatin, A.
name: Lu, C. -C.
name: Marandon, V.
name: Marcowith, A.
name: Masbou, J.
name: Maurin, G.
name: Maxted, N.
name: Mayer, M.
name: McComb, T. J. L.
name: Medina, M. C.
name: Méhault, J.
name: Moderski, R.
name: Mohamed, M.
name: Moulin, E.
name: Naumann, C. L.
name: Naumann-Godo, M.
name: de Naurois, M.
name: Nedbal, D.
name: Nekrassov, D.
name: Nguyen, N.
name: Nicholas, B.
name: Niemiec, J.
name: Nolan, S. J.
name: Ohm, S.
name: Wilhelmi, E. de Oña
name: Opitz, B.
name: Ostrowski, M.
name: Oya, I.
name: Panter, M.
name: Arribas, M. Paz
name: Pekeur, N. W.
name: Pelletier, G.
name: Perez, J.
name: Petrucci, P. -O.
name: Peyaud, B.
name: Pita, S.
name: Pühlhofer, G.
name: Punch, M.
name: Quirrenbach, A.
name: Raue, M.
name: Reimer, A.
name: Reimer, O.
name: Renaud, M.
name: Reyes, R. de los
name: Rieger, F.
name: Ripken, J.
name: Rob, L.
name: Rosier-Lees, S.
name: Rowell, G.
name: Rudak, B.
name: Rulten, C. B.
name: Sahakian, V.
name: Sanchez, D. A.
name: Santangelo, A.
name: Schlickeiser, R.
name: Schulz, A.
name: Schwanke, U.
name: Schwarzburg, S.
name: Schwemmer, S.
name: Sheidaei, F.
name: Skilton, J. L.
name: Sol, H.
name: Spengler, G.
name: Stawarz, Ł.
name: Steenkamp, R.
name: Stegmann, C.
name: Stinzing, F.
name: Stycz, K.
name: Sushch, I.
name: Szostek, A.
name: Tavernet, J. -P.
name: Terrier, R.
name: Tluczykont, M.
name: Valerius, K.
name: van Eldik, C.
name: Vasileiadis, G.
name: Venter, C.
name: Viana, A.
name: Vincent, P.
name: Völk, H. J.
name: Volpe, F.
name: Vorobiov, S.
name: Vorster, M.
name: Wagner, S. J.
name: Ward, M.
name: White, R.
name: Wierzcholska, A.
name: Zacharias, M.
name: Zajczyk, A.
name: Zdziarski, A. A.
name: Zech, A.
name: Zechlin, H. -S.
name: Montmerle, T.
Publisher: name: arXiv
Year: 2012
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences
subject: FOS: Physical sciences

description: The massive binary system Eta Carinae and the surrounding HII complex, the Carina Nebula, are potential particle acceleration sites from which very-high-energy (VHE; E &gt; 100 GeV) γ-ray emission could be expected. This paper presents data collected during VHE γ-ray observations with the H.E.S.S. telescope array from 2004 to 2010, which cover a full orbit of Eta Carinae. In the 33.1-hour data set no hint of significant γ-ray emission from Eta Carinae has been found and an upper limit on the γ-ray flux of 7.7 x 10-13 ph cm-2 s-1 (99% confidence level) is derived above the energy threshold of 470 GeV. Together with the detection of high-energy (HE; 0.1 GeV &gt; E &gt; 100 GeV) γ-ray emission by the Fermi-LAT up to 100 GeV, and assuming a continuation of the average HE spectral index into the VHE domain, these results imply a cut-off in the γ-ray spectrum between the HE and VHE γ-ray range. This could be caused either by a cut-off in the accelerated particle distribution or by severe γ-γ absorption losses in the wind collision region. Furthermore, the search for extended γ-ray emission from the Carina Nebula resulted in an upper limit on the γ-ray flux of 4.2 x 10-12 ph cm-2 s-1 (99% confidence level). The derived upper limit of ~23 on the cosmic-ray enhancement factor is compared with results found for the old-age mixed-morphology supernova remnant W 28.
description: 8 pages, 3 figures, accepted for publication in MNRAS