학술논문
Curvature in the very-high energy gamma-ray spectrum of M87
Document Type
Working Paper
Author
Collaboration, H. E. S. S.; Aharonian, F.; Benkhali, F. Ait; Aschersleben, J.; Ashkar, H.; Backes, M.; Martins, V. Barbosa; Batzofin, R.; Becherini, Y.; Berge, D.; Bernlöhr, K.; Böttcher, M.; Boisson, C.; Bolmont, J.; de Lavergne, M. de Bony; Bradascio, F.; Brose, R.; Brun, F.; Bruno, B.; Burger-Scheidlin, T. Bulik C.; Bylund, T.; Casanova, S.; Cecil, R.; Celic, J.; Cerruti, M.; Chand, T.; Chandra, S.; Chen, A.; Chibueze, J.; Chibueze, O.; Collins, T.; Cotter, G.; Mbarubucyeye, J. Damascene; Djannati-Ataï, A.; Djuvsland, J.; Dmytriiev, A.; Egberts, K.; Einecke, S.; Fegan, S.; Fontaine, G.; Funk, S.; Gabici, S.; Glicenstein, J. F.; Glombitza, J.; Grolleron, G.; Haerer, L.; Hofmann, W.; Holch, T. L.; Holler, M.; Horns, D.; Jamrozy, M.; Jankowsky, F.; Joshi, V.; Jung-Richardt, I.; Kasai, E.; Katarzyński, K.; Khatoon, R.; Khélifi, B.; Kluźniak, W.; Komin, Nu.; Kosack, K.; Kostunin, D.; Kundu, A.; Lang, R. G.; Stum, S. Le; Leitl, F.; Lemière, A.; Lemoine-Goumard, M.; Lenain, J. -P.; Lypova, I.; Luashvili, A.; Mackey, J.; Malyshev, D.; Martí-Devesa, G.; Marx, R.; Mehta, A.; Meyer, M.; Mitchell, A.; Moderski, R.; Moghadam, M. O.; Mohrmann, L.; Montanari, A.; Moulin, E.; Murach, T.; de Naurois, M.; Niemiec, J.; Ohm, S.; Olivera-Nieto, L.; Wilhelmi, E. de Ona; Panny, S.; Panter, M.; Parsons, R. D.; Pensec, U.; Pita, S.; Pühlhofer, G.; Punch, M.; Quirrenbach, A.; Regeard, M.; Reimer, A.; Reimer, O.; Ren, H.; Reville, B.; Rieger, F.; Rudak, B.; Ruiz-Velasco, E.; Sahakian, V.; Salzmann, H.; Santangelo, A.; Sasaki, M.; Schüssler, F.; Schutte, H. M.; Shapopi, J. N. S.; Sol, H.; Spencer, S.; Stawarz, Ł.; Steenkamp, R.; Steinmassl, S.; Steppa, C.; Streil, K.; Takahashi, T.; Tanaka, T.; Taylor, A. M.; Terrier, R.; Tsirou, M.; van Eldik, C.; Venter, C.; Vink, J.; Wach, T.; Wagner, S. J.; Wierzcholska, A.; Zacharias, M.; Zdziarski, A. A.; Zech, A.; Zilberman, P.; Zywucka, N.
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Subject
Language
Abstract
The radio galaxy M87 is a variable very-high energy (VHE) gamma-ray source, exhibiting three major flares reported in 2005, 2008, and 2010. Despite extensive studies, the origin of the VHE gamma-ray emission is yet to be understood. In this study, we investigate the VHE gamma-ray spectrum of M87 during states of high gamma-ray activity, utilizing 20.2$\,$ hours the H.E.S.S. observations. Our findings indicate a preference for a curved spectrum, characterized by a log-parabola model with extra-galactic background light (EBL) model above 0.3$\,$TeV at the 4$\sigma$ level, compared to a power-law spectrum with EBL. We investigate the degeneracy between the absorption feature and the EBL normalization and derive upper limits on EBL models mainly sensitive in the wavelength range 12.4$\,$$\mu$m - 40$\,$$\mu$m.
Comment: 10 pages, 7 figures. Accepted for publication in A&A. Corresponding authors: Victor Barbosa Martins, Rahul Cecil, Iryna Lypova, Manuel Meyer, Perri Zilberman. Supplementary material: https://zenodo.org/records/10781524
Comment: 10 pages, 7 figures. Accepted for publication in A&A. Corresponding authors: Victor Barbosa Martins, Rahul Cecil, Iryna Lypova, Manuel Meyer, Perri Zilberman. Supplementary material: https://zenodo.org/records/10781524