Discovery of a VHE gamma-ray source coincident with the supernova remnant CTB 37A
Santangelo, A.; Quirrenbach, A.; Ripken, J.; Carrigan, S.; Farnier, C.; Funk, S.; Lemoine-Goumard, M.; Reimer, O.; Tibolla, O.; Venter, C.; Schlickeiser, R.; Petrucci, P. -O.; Giebels, B.; Stawarz, Ł.; Fontaine, G.; Benbow, W.; Hauser, M.; Boisson, C.; Aharonian, F.; Akhperjanian, A. G.; Bazer-Bachi, A. R.; Beilicke, M.; Bernlöhr, K.; Braun, I.; Chadwick, P. M.; Chounet, L. -M.; Cornils, R.; Costamante, L.; Degrange, B.; Djannati-Ataï, A.; O'C. Drury, L.; Dubus, G.; Emmanoulopoulos, D.; Espigat, P.; Feinstein, F.; Gallant, Y. A.; Glicenstein, J. F.; Goret, P.; Hadjichristidis, C.; Heinzelmann, G.; Henri, G.; Hermann, G.; Hinton, J. A.; Hofmann, W.; Holleran, M.; Horns, D.; de Jager, O. C.; Khélifi, B.; Komin, Nu.; Latham, I. J.; Martineau-Huynh, O.; Lohse, T.; Marcowith, A.; Masterson, C.; McComb, T. J. L.; de Naurois, M.; Nolan, S. J.; Orford, K. J.; Osborne, J. L.; Panter, M.; Pelletier, G.; Pita, S.; Pühlhofer, G.; Punch, M.; Raubenheimer, B. C.; Raue, M.; Rayner, S. M.; Rob, L.; Rowell, G.; Sahakian, V.; Schwanke, U.; Sol, H.; Steenkamp, R.; Stegmann, C.; Tavernet, J. -P.; Terrier, R.; Vasileiadis, G.; Vincent, P.; Völk, H. J.; Wagner, S. J.; Ward, M.; Lamanna, G.; Vialle, J. P.; Kendziorra, E.; Renaud, M.; Barres de Almeida, U.; de Oña Wilhelmi, E.; Pedaletti, G.; Behera, B.; Borrel, V.; Brucker, J.; Bühler, R.; Bulik, T.; Büsching, I.; Boutelier, T.; Clapson, A. C.; Coignet, G.; Dalton, M.; Dickinson, H. J.; Domainko, W.; Dubois, F.; Dyks, J.; Egberts, K.; Fiasson, A.; Förster, A.; Füßling, M.; Gabici, S.; Glück, B.; Hauser, D.; Hoffmann, A.; Hoppe, S.; Jacholkowska, A.; Jung, I.; Katarzyński, K.; Kaufmann, S.; Kerschhaggl, M.; Khangulyan, D.; Keogh, D.; Kosack, K.; Lenain, J. -P.; Maurin, D.; Moderski, R.; Moulin, E.; Naumann-Godo, M.; Nedbal, D.; Nekrassov, D.; Ohm, S.; Ostrowski, M.; Rieger, F.; Rosier-Lees, S.; Rudak, B.; Ruppel, J.; Schöck, F. M.; Schwarzburg, S.; Schwemmer, S.; Shalchi, A.; Skilton, J. L.; Superina, G.; Tam, P. H.; van Eldik, C.; Vivier, M.; Volpe, F.; Zdziarski, A. A.; Zech, A.; Nakajima, H.; Brion, E.; Martin, J. M.; Olive, J. -P.; Schröder, R.; Spangler, D.; Chaves, R.
Germany, Ireland, Armenia, United Kingdom, France, Poland, South Africa, United States, Japan, Czech Republic, Australia, Namibia
Abstract
Aims: The supernova remnant (SNR) complex CTB 37 is an interesting candidate for observations with very high energy (VHE) γ-ray telescopes such as HESS. In this region, three SNRs are seen. One of them is potentially associated with several molecular clouds, a circumstance that can be used to probe the acceleration of hadronic cosmic rays.
Methods: This region was observed with the HESS Cherenkov telescopes and the data were analyzed with standard HESS procedures. Recent X-ray observations with Chandra and XMM-Newton were used to search for X-ray counterparts.
Results: The discovery of a new VHE γ-ray source HESS J1714-385 coincident with the remnant CTB 37A is reported. The energy spectrum is well described by a power-law with a photon index of Γ = 2.30 ± 0.13 and a differential flux at 1 TeV of Φ0 = (8.7 ± 1.0stat ± 1.8sys) × 10-13 cm-2 s-1 TeV-1. The integrated flux above 1 TeV is equivalent to 3% of the flux of the Crab nebula above the same energy. This VHE γ-ray source is a counterpart candidate for the unidentified EGRET source 3EG J1714-3857. The observed VHE emission is consistent with the molecular gas distribution around CTB 37A; a close match is expected in a hadronic scenario for γ-ray production. The X-ray observations reveal the presence of thermal X-rays from the NE part of the SNR. In the NW part of the remnant, an extended non-thermal X-ray source, CXOU J171419.8-383023, is discovered as well. Possible connections of the X-ray emission to the newly found VHE source are discussed.