Aharonian F, Ait Benkhali F, Aschersleben J, Ashkar H, Backes M, Martins VB, Batzofin R, Becherini Y, Berge D, Bernlohr K, Bottcher M, Boisson C, Bolmont J, De Lavergne MDB, Bradascio F, Brose R, Brun F, Bruno B, Bulik T, Burger-Scheidlin 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 JD, Djannati-Atai A, Djuvsland J, Dmytriiev A, Egberts K, Einecke S, Fegan S, Fontaine G, Funk S, Gabici S, Glicenstein JF, Glombitza J, Grolleron G, Haerer L, Hofmann W, Holch TL, Holler M, Horns D, Jamrozy M, Jankowsky F, Joshi V, Jung-Richardt I, Kasai E, Katarzyński K, Khatoon R, Khelifi B, Kluźniak W, Komin N, Kosack K, Kostunin D, Kundu A, Guedes Lang R, Le Stum S, Leitl F, Lemiere A, Lemoine-Goumard M, Lenain JP, Lypova I, Luashvili A, MacKey J, Malyshev D, Marti-Devesa G, Marx R, Mehta A, Meyer M, Mitchell A, Moderski R, Moghadam MO, Mohrmann L, Montanari A, Moulin E, Murach T, De Naurois M, Niemiec J, Ohm S, Olivera-Nieto L, Wilhelmi EDO, Panny S, Panter M, Parsons RD, Pensec U, Pita S, Puhlhofer 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, Schussler F, Schutte HM, Shapopi JN, Sol H, Spencer S, Stawarz L, Steenkamp R, Steinmassl S, Steppa C, Streil K, Takahashi T, Tanaka T, Taylor AM, Terrier R, Tsirou M, van Eldik C, Venter C, Vink J, Wach T, Wagner SJ, Wierzcholska A, Zacharias M, Zdziarski AA, Zech A, Zilberman P, Zywucka N (2024)
Publication Type: Journal article
Publication year: 2024
Book Volume: 685
Article Number: A96
DOI: 10.1051/0004-6361/202348913
The radio galaxy M 87 is a variable very-high energy (VHE) gamma-ray source, exhibiting three major flares, which were reported in 2005, 2008, and 2010. Despite extensive studies, the origin of the VHE gamma-ray emission is not yet fully understood. In this study, we investigate the VHE gamma-ray spectrum of M 87 during states of high gamma-ray activity, utilizing 20.2 h of 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 4σ 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 that are mainly sensitive in the wavelength range of 12.4 μm-40 μm.
APA:
Aharonian, F., Ait Benkhali, F., Aschersleben, J., Ashkar, H., Backes, M., Martins, V.B.,... Zywucka, N. (2024). Curvature in the very-high energy gamma-ray spectrum of M 87. Astronomy & Astrophysics, 685. https://doi.org/10.1051/0004-6361/202348913
MLA:
Aharonian, F., et al. "Curvature in the very-high energy gamma-ray spectrum of M 87." Astronomy & Astrophysics 685 (2024).
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