LMC N132D: A mature supernova remnant with a power-law gamma-ray spectrum extending beyond 8 TeV

Abdalla H, Aharonian F, Mitchell A, Benkhali FA, Anguner EO, Arcaro C, Armand C, Armstrong T, Ashkar H, Backes M, Baghmanyan , Martins VB, Barnacka A, Barnard M, Batzofin R, Becherini Y, Berge D, Bernloehr K, Bi B, Boettcher M, Boisson C, Bolmont J, De Lavergne MDB, Breuhaus M, Brose R, Brun F, Bulik T, Bylund T, Cangemi F, Caroff S, Casanova S, Catalano J, Chambery P, Chand T, Chen A, Cotter G, Curylo M, Mbarubucyeye JD, Davids ID, Davies J, Devin J, Djannati-Atai A, Dmytriiev A, Donath A, Doroshenko , Dreyer L, Du Plessis L, Duffy C, Egberts K, Einecke S, Ernenwein JP, Fegan S, Feijen K, Fiasson A, De Clairfontaine GF, Fontaine G, Lott F, Fussling M, Funk S, Gabici S, Gallant YA, Giavitto G, Giunti L, Glawion D, Glicenstein JF, Grondin MH, Hattingh S, Haupt M, Hermann G, Hinton JA, Hofmann W, Hoischen C, Holch TL, Holler M, Hoerbe M, Horns D, Huang Z, Huber D, Jamrozy M, Jankowsky F, Joshi , Jung-Richardt , Kasai E, Katarzyński K, Katz U, Khangulyan D, Khelifi B, Klepser S, Kluzniak W, Komin N, Konno R, Kosack K, Kostunin D, Kreter M, Mezek GK, Kundu A, Lamanna G, Le Stum S, Lemiere A, Lemoine-Goumard M, Lenain JP, Leuschner F, Levy C, Lohse T, Luashvili A, Lypova , Mackey J, Majumdar J, Malyshev D, Malyshev D, Marandon , Marchegiani P, Marcowith A, Mares A, Martí-Devesa G, Marx R, Maurin G, Meintjes PJ, Meyer M, Mitchell A, Moderski R, Mohrmann L, Montanari A, Moore C, Moulin E, Muller J, Murach T, Nakashima K, De Naurois M, Nayerhoda A, Ndiyavala H, Niemiec J, Noel AP, O'Brien P, Oberholzer L, Odaka H, Ohm S, Olivera-Nieto L, Wilhelmi EDO, Ostrowski M, Panny S, Panter M, Parsons RD, Peron G, Pita S, Poireau , Prokhorov DA, Prokoph H, Pühlhofer G, Punch M, Quirrenbach A, Reichherzer P, Reimer A, Reimer O, Remy Q, Renaud M, Reville B, Rieger F, Romoli C, Rowell G, Rudak B, Ricarte HR, Ruiz-Velasco E, Sahakian , Sailer S, Salzmann H, Sanchez DA, Santangelo A, Sasaki M, Schäfer J, Schuessler F, Schutte HM, Schwanke U, Senniappan M, Seyffert AS, Shapopi JNS, Shiningayamwe K, Simoni R, Sinha A, Sol H, Specovius A, Spencer ST, Spir-Jacob M, Stawarz L, Steenkamp R, Stegmann C, Steinmassl S, Steppa C, Sun L, Takahashi T, Tanaka T, Tavernier T, Taylor AM, Terrier R, Thiersen JHE, Thorpe-Morgan C, Tluczykont M, Tomankova L, Tsirou M, Tsuji N, Tuffs R, Uchiyama Y, Van Der Walt DJ, van Eldik C, Van Rensburg C, Van Soelen B, Vasileiadis G, Veh J, Venter C, Vincent P, Vink J, Voelk HJ, Wagner SJ, Watson J, Werner F, White R, Wierzcholska A, Wong YW, Yassin H, Yusafzai A, Zacharias M, Zanin R, Zargaryan D, Zdziarski AA, Zech A, Zhu SJ, Zmija A, Zouari S, Żywucka N (2021)


Publication Type: Journal article

Publication year: 2021

Journal

Book Volume: 655

Article Number: A7

DOI: 10.1051/0004-6361/202141486

Abstract

Context. Supernova remnants (SNRs) are commonly thought to be the dominant sources of Galactic cosmic rays up to the knee of the cosmic-ray spectrum at a few PeV. Imaging Atmospheric Cherenkov Telescopes have revealed young SNRs as very-high-energy (VHE, >100 GeV) gamma-ray sources, but for only a few SNRs the hadronic cosmic-ray origin of their gamma-ray emission is indisputably established. In all these cases, the gamma-ray spectra exhibit a spectral cutoff at energies much below 100 TeV and thus do not reach the PeVatron regime. Aims. The aim of this work was to achieve a firm detection for the oxygen-rich SNR LMC N132D in the VHE gamma-ray domain with an extended set of data, and to clarify the spectral characteristics and the localization of the gamma-ray emission from this exceptionally powerful gamma-ray-emitting SNR. Methods. We analyzed 252 h of High Energy Stereoscopic System (H.E.S.S.) observations towards SNR N132D that were accumulated between December 2004 and March 2016 during a deep survey of the Large Magellanic Cloud, adding 104 h of observations to the previously published data set to ensure a > 5σ detection. To broaden the gamma-ray spectral coverage required for modeling the spectral energy distribution, an analysis of Fermi-LAT Pass 8 data was also included. Results. We unambiguously detect N132D at VHE with a significance of 5.7σ. We report the results of a detailed analysis of its spectrum and localization based on the extended H.E.S.S. data set. The joint analysis of the extended H.E.S.S and Fermi-LAT data results in a spectral energy distribution in the energy range from 1.7 GeV to 14.8 TeV, which suggests a high luminosity of N132D at GeV and TeV energies. We set a lower limit on a gamma-ray cutoff energy of 8 TeV with a confidence level of 95%. The new gamma-ray spectrum as well as multiwavelength observations of N132D when compared to physical models suggests a hadronic origin of the VHE gamma-ray emission. Conclusions. SNR N132D is a VHE gamma-ray source that shows a spectrum extending to the VHE domain without a spectral cutoff at a few TeV, unlike the younger oxygen-rich SNR Cassiopeia A. The gamma-ray emission is best explained by a dominant hadronic component formed by diffusive shock acceleration. The gamma-ray properties of N132D may be affected by an interaction with a nearby molecular cloud that partially lies inside the 95% confidence region of the source position.

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APA:

Abdalla, H., Aharonian, F., Mitchell, A., Benkhali, F.A., Anguner, E.O., Arcaro, C.,... Żywucka, N. (2021). LMC N132D: A mature supernova remnant with a power-law gamma-ray spectrum extending beyond 8 TeV. Astronomy & Astrophysics, 655. https://doi.org/10.1051/0004-6361/202141486

MLA:

Abdalla, H., et al. "LMC N132D: A mature supernova remnant with a power-law gamma-ray spectrum extending beyond 8 TeV." Astronomy & Astrophysics 655 (2021).

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