posted on 2018-05-09, 10:19authored byH. Abdalla, A. Abramowski, F. Aharonian, F. A. Benkhali, A. G. Akhperjanian, T. Andersson, O. Anguener, M. Arrieta, P. Aubert, M. Backes, A. Balzer, M. Barnard, Y. Becherini, J. B. Tjus, D. Berge, S. Bernhard, K. Bernloehr, R. Blackwell, M. Boettcher, C. Boisson, J. Bolmont, P. Bordas, J. Bregeon, F. Brun, P. Brun, M. Bryan, T. Bulik, M. Capasso, J. Carr, S. Casanova, M. Cerruti, N. Chakraborty, R. Chalme-Calvet, R. C. G. Chaves, A. Chen, J. Chevalier, M. Chretien, S. Colafrancesco, G. Cologna, B. Condon, J. Conrad, Y. Cui, I. D. Davids, J. Decock, B. Degrange, C. Deil, J. Devin, P. deWilt, L. Dirson, A. Djannati-Atai, W. Domainko, A. Donath, L. O. Drury, G. Dubus, K. Dutson, J. Dyks, T. Edwards, K. Egberts, P. Eger, J.-P. Ernenwein, S. Eschbach, C. Farnier, S. Fegan, M. V. Fernandes, A. Fiasson, G. Fontaine, A. Foerster, S. Funk, M. Fuessling, S. Gabici, M. Gajdus, Y. A. Gallant, T. Garrigoux, G. Giavitto, B. Giebels, J. F. Glicenstein, D. Gottschall, A. Goyal, M.-H. Grondin, D. Hadasch, J. Hahn, M. Haupt, J. Hawkes, G. Heinzelmann, G. Henri, G. Hermann, O. Hervet, J. A. Hinton, W. Hofmann, C. Hoischen, M. Holler, D. Horns, A. Ivascenko, A. Jacholkowska, M. Jamrozy, M. Janiak, D. Jankowsky, F. Jankowsky, M. Jingo, T. Jogler, L. Jouvin, I. Jung-Richardt, M. A. Kastendieck, K. Katarzynski, U. Katz, D. Kerszberg, B. Khelifi, M. Kieffer, J. King, S. Klepser, D. Klochkov, W. Kluzniak, D. Kolitzus, N. Komin, K. Kosack, S. Krakau, M. Kraus, F. Krayzel, P. P. Krueger, H. Laffon, G. Lamanna, J. Lau, J.-P. Lees, J. Lefaucheur, V. Lefranc, A. Lemiere, M. Lemoine-Goumard, J.-P. Lenain, E. Leser, T. Lohse, M. Lorentz, R. Liu, R. Lopez-Coto, I. Lypova, V. Marandon, A. Marcowith, C. Mariaud, R. Marx, G. Maurin, N. Maxted, M. Mayer, P. J. Meintjes, M. Meyer, A. M. W. Mitchell, R. Moderski, M. Mohamed, L. Mohrmann, K. Mora, E. Moulin, T. Murach, M. de Naurois, F. Niederwanger, J. Niemiec, L. Oakes, Paul O'Brien, H. Odaka, S. Oettl, S. Ohm, M. Ostrowski, I. Oya, M. Padovani, M. Panter, R. D. Parsons, N. W. Pekeur, G. Pelletier, C. Perennes, P.-O. Petrucci, B. Peyaud, Q. Piel, S. Pita, H. Poon, D. Prokhorov, H. Prokoph, G. Puehlhofer, M. Punch, A. Quirrenbach, S. Raab, A. Reimer, O. Reimer, M. Renaud, R. de los Reyes, F. Rieger, C. Romoli, S. Rosier-Lees, G. Rowell, B. Rudak, C. B. Rulten, V. Sahakian, D. Salek, D. A. Sanchez, A. Santangelo, M. Sasaki, R. Schlickeiser, F. Schuessler, A. Schulz, U. Schwanke, S. Schwemmer, M. Settimo, A. S. Seyffert, N. Shafi, I. Shilon, R. Simoni, H. Sol, F. Spanier, G. Spengler, F. Spies, L. Stawarz, R. Steenkamp, C. Stegmann, F. Stinzing, K. Stycz, I. Sushch, J.-P. Tavernet, T. Tavernier, A. M. Taylor, R. Terrier, L. Tibaldo, D. Tiziani, M. Tluczykont, C. Trichard, R. Tuffs, Y. Uchiyama, D. J. van der Walt, C. van Eldik, C. van Rensburg, B. van Soelen, G. Vasileiadis, J. Veh, C. Venter, A. Viana, P. Vincent, J. Vink, F. Voisin, H. J. Voelk, T. Vuillaume, Z. Wadiasingh, S. J. Wagner, P. Wagner, R. M. Wagner, R. White, A. Wierzcholska, P. Willmann, A. Woernlein, D. Wouters, R. Yang, V. Zabalza, D. Zaborov, M. Zacharias, A. A. Zdziarski, A. Zech, F. Zefi, A. Ziegler, N. Zywucka, J. Katsuta
The supernova remnant (SNR) W49B originated from a core-collapse supernova that occurred between one and four thousand years ago, and subsequently evolved into a mixed-morphology remnant, which is interacting with molecular clouds (MC). Gamma-ray observations of SNR-MC associations are a powerful tool to constrain the origin of Galactic cosmic rays, as they can probe the acceleration of hadrons through their interaction with the surrounding medium and subsequent emission of non-thermal photons. We report the detection of a γ-ray source coincident with W49B at very high energies (VHE; E > 100 GeV) with the H.E.S.S. Cherenkov telescopes together with a study of the source with five years of Fermi-LAT high-energy γ-ray (0.06–300 GeV) data. The smoothly connected, combined source spectrum, measured from 60 MeV to multi-TeV energies, shows two significant spectral breaks at 304 ± 20 MeV and 8.4−2.5+2.2 GeV; the latter is constrained by the joint fit from the two instruments. The detected spectral features are similar to those observed in several other SNR-MC associations and are found to be indicative of γ-ray emission produced through neutral-pion decay.
History
Citation
Astronomy and Astrophysics, 2018, 612, A5
Author affiliation
/Organisation/COLLEGE OF SCIENCE AND ENGINEERING/Department of Physics and Astronomy