Exploring a SNR/molecular cloud association within HESS J1745–303

¹ Max-Planck-Institut für Kernphysik, PO Box 103980, 69029 Heidelberg, Germany e-mail: Karl.Kosack@mpi-hd.mpg.de
² Dublin Institute for Advanced Studies, 5 Merrion Square, Dublin 2, Ireland
³ Yerevan Physics Institute, 2 Alikhanian Brothers St., 375036 Yerevan, Armenia
⁴ University of Durham, Department of Physics, South Road, Durham DH1 3LE, UK
⁵ Centre d'Étude Spatiale des Rayonnements, CNRS/UPS, 9 Av. du Colonel Roche, BP 4346, 31029 Toulouse Cedex 4, France
⁶ Landessternwarte, Universität Heidelberg, Königstuhl, 69117 Heidelberg, Germany
⁷ Universität Hamburg, Institut für Experimentalphysik, Luruper Chaussee 149, 22761 Hamburg, Germany
⁸ Institut für Physik, Humboldt-Universität zu Berlin, Newtonstr. 15, 12489 Berlin, Germany
⁹ LUTH, Observatoire de Paris, CNRS, Université Paris Diderot, 5 place Jules Janssen, 92190 Meudon, France
¹⁰ DAPNIA/DSM/CEA, CE Saclay, 91191 Gif-sur-Yvette Cedex, France
¹¹ Nicolaus Copernicus Astronomical Center, Warsaw, Poland
¹² Unit for Space Physics, North-West University, Potchefstroom 2520, South Africa
¹³ Laboratoire d'Astrophysique de Grenoble, INSU/CNRS, Université Joseph Fourier, BP 53, 38041 Grenoble Cedex 9, France
¹⁴ Laboratoire Leprince-Ringuet, École Polytechnique, CNRS/ IN2P3, 91128 Palaiseau, France
¹⁵ Laboratoire d'Annecy-le-Vieux de Physique des Particules, CNRS/IN2P3, 9 chemin de Bellevue, BP 110, 74941 Annecy-le-Vieux Cedex, France
¹⁶ European Associated Laboratory for Gamma-Ray Astronomy, jointly supported by CNRS and MPG
¹⁷ Astroparticule et Cosmologie (APC), CNRS, Université Paris 7 Denis Diderot, 10 rue Alice Domon et Léonie Duquet, 75205 Paris Cedex 13; (UMR 7164 (CNRS, Université Paris VII, CEA, Observatoire de Paris)) , France
¹⁸ Laboratoire de Physique Théorique et Astroparticules, CNRS/IN2P3, Université Montpellier II, CC 70, Place Eugène Bataillon, 34095 Montpellier Cedex 5, France e-mail: Armand.Fiasson@LPTA.in2p3.fr
¹⁹ Kavli Institute for Particle Astrophysics and Cosmology, SLAC, 2575 Sand Hill Road, Menlo-Park, CA-94025, USA
²⁰ Universität Erlangen-Nürnberg, Physikalisches Institut, Erwin-Rommel-Str. 1, 91058 Erlangen, Germany
²¹ School of Physics & Astronomy, University of Leeds, Leeds LS2 9JT, UK
²² Institut für Astronomie und Astrophysik, Universität Tübingen, Sand 1, 72076 Tübingen, Germany
²³ Toruń Centre for Astronomy, Nicolaus Copernicus University, Toruń, Poland
²⁴ LPNHE, Université Pierre et Marie Curie Paris 6, Université Denis Diderot Paris 7, CNRS/IN2P3, 4 place Jussieu, 75252 Paris Cedex 5, France
²⁵ Institute of Particle and Nuclear Physics, Charles University, V Holesovickach 2, 180 00 Prague 8, Czech Republic
²⁶ Obserwatorium Astronomiczne, Uniwersytet Jagielloński, Kraków, Poland
²⁷ School of Chemistry & Physics, University of Adelaide, Adelaide 5005, Australia
²⁸ Institut für Theoretische Physik, Lehrstuhl IV: Weltraum und Astrophysik, Ruhr-Universität Bochum, 44780 Bochum, Germany
²⁹ University of Namibia, Private Bag 13301, Windhoek, Namibia

Received: 11 December 2007
Accepted: 20 February 2008

Abstract

Aims. HESS J1745-303 is an extended, unidentified VHE (very high energy) gamma-ray source discovered using HESS in the Galactic Plane Survey. Since no obvious counterpart has previously been found in longer-wavelength data, the processes that power the VHE emission are not well understood.

Methods. Combining the latest VHE data with recent XMM-Newton observations and a variety of source catalogs and lower-energy survey data, we attempt to match (from an energetic and positional standpoint) the various parts of the emission of HESS J1745-303 with possible candidates.

Results. Though no single counterpart is found to fully explain the VHE emission, we postulate that at least a fraction of the VHE source may be explained by a supernova-remnant/molecular-cloud association and/or a high-spin-down-flux pulsar.