A new SNR with TeV shell-type morphology: HESS J1731-347

Klochkov, D.; Santangelo, A.; Quirrenbach, A.; Ripken, J.; Carrigan, S.; Conrad, J.; Farnier, C.; Reimer, A.; Reimer, O.; Ryde, F.; Venter, C.; Schlickeiser, R.; Petrucci, P. -O.; Giebels, B.; Stawarz, Ł.; Sikora, M.; Fontaine, G.; Daniel, M. K.; Hauser, M.; Boisson, C.; Aharonian, F.; Akhperjanian, A. G.; Bernlöhr, K.; Chadwick, P. M.; Chounet, L. -M.; Degrange, B.; Djannati-Ataï, A.; Dubus, G.; Espigat, P.; Feinstein, F.; Gallant, Y. A.; Glicenstein, J. F.; Goret, P.; Heinzelmann, G.; Henri, G.; Hermann, G.; Hinton, J. A.; Hofmann, W.; Horns, D.; de Jager, O. C.; Khélifi, B.; Komin, Nu.; Lohse, T.; Marcowith, A.; McComb, T. J. L.; de Naurois, M.; Nolan, S. J.; Panter, M.; Pelletier, G.; Pita, S.; Pühlhofer, G.; Punch, M.; Raue, M.; Rayner, S. M.; Rob, L.; Rowell, G.; Sahakian, V.; Schwanke, U.; Sol, H.; Steenkamp, R.; Stegmann, C.; Tavernet, J. -P.; Terrier, R.; Tluczykont, M.; Vasileiadis, G.; Vincent, P.; Völk, H. J.; Wagner, S. J.; Ward, M.; Heinz, S.; Kossakowski, R.; Lamanna, G.; Vialle, J. P.; Acero, F.; Chaves, R. C. G.; Schulz, A.; Renaud, M.; Cerruti, M.; Barres de Almeida, U.; Pedaletti, G.; Anton, G.; Becherini, Y.; Behera, B.; Bochow, A.; Bolmont, J.; Brucker, J.; Brun, F.; Brun, P.; Bulik, T.; Büsching, I.; Charbonnier, A.; Cheesebrough, A.; Clapson, A. C.; Coignet, G.; Dalton, M.; Davids, I. D.; Deil, C.; Dickinson, H. J.; Domainko, W.; Dubois, F.; Dyks, J.; Dyrda, M.; Egberts, K.; Eger, P.; Fallon, L.; Fegan, S.; Fiasson, A.; Förster, A.; Füßling, M.; Gérard, L.; Gerbig, D.; Glück, B.; Göring, D.; Hoffmann, A.; Hofverberg, P.; Jacholkowska, A.; Jahn, C.; Jung, I.; Katarzyński, K.; Katz, U.; Kaufmann, S.; Khangulyan, D.; Keogh, D.; Kluźniak, W.; Kneiske, T.; Kosack, K.; Marandon, V.; Masbou, J.; Maurin, D.; Medina, M. C.; Méhault, J.; Moderski, R.; Moulin, E.; Naumann-Godo, M.; Nedbal, D.; Nekrassov, D.; Nicholas, B.; Niemiec, J.; Ohm, S.; Ostrowski, M.; Paz Arribas, M.; Rieger, F.; Rosier-Lees, S.; Rudak, B.; Rulten, C. B.; Ruppel, J.; Schöck, F. M.; Schwarzburg, S.; Schwemmer, S.; Sushch, I.; Skilton, J. L.; Stinzing, F.; Szostek, A.; van Eldik, C.; Volpe, F.; Vorobiov, S.; Zdziarski, A. A.; Zech, A.; H. E. S. S. Collaboration; Abramowski, A.; Balzer, A.; Barnacka, A.; Bordas, P.; Casanova, S.; Cologna, G.; Dutson, K.; Fernandes, M. V.; Häffner, S.; Holler, M.; Jamrozy, M.; Kastendieck, M. A.; Laffon, H.; Lopatin, A.; Lu, C. -C.; Maxted, N.; Opitz, B.; Oya, I.; de los Reyes, R.; Spengler, G.; Stycz, K.; Valerius, K.; Viana, A.; Vorster, M.; White, R.; Wierzcholska, A.; Zacharias, M.; Zechlin, H. -S.; Becker, J.; Gast, H.; Hague, J. D.; Hampf, D.; Lennarz, D.; Naumann, C. L.; Nguyen, N.; Zajczyk, A.; Drury, L. O'C.; de Oña Wilhelmi, D.

Abstract


Aims: The recent discovery of the radio shell-type supernova remnant (SNR), G353.6-0.7, in spatial coincidence with the unidentified TeV source HESS J1731-347 has motivated further observations of the source with the High Energy Stereoscopic System (HESS) Cherenkov telescope array to test a possible association of the γ-ray emission with the SNR.
Methods: With a total of 59 h of observation, representing about four times the initial exposure available in the discovery paper of HESS J1731-347, the γ-ray morphology is investigated and compared with the radio morphology. An estimate of the distance is derived by comparing the interstellar absorption derived from X-rays and the one obtained from 12CO and HI observations.
Results: The deeper γ-ray observation of the source has revealed a large shell-type structure with similar position and extension (r ~ 0.25°) as the radio SNR, thus confirming their association. By accounting for the HESS angular resolution and projection effects within a simple shell model, the radial profile is compatible with a thin, spatially unresolved, rim. Together with RX J1713.7-3946, RX J0852.0-4622 and SN 1006, HESS J1731-347 is now the fourth SNR with a significant shell morphology at TeV energies. The derived lower limit on the distance of the SNR of 3.2 kpc is used together with radio and X-ray data to discuss the possible origin of the γ-ray emission, either via inverse Compton scattering of electrons or the decay of neutral pions resulting from proton-proton interaction.

2011 Astronomy and Astrophysics
XMM-Newton 88