Constraining the cosmic-ray pressure in the inner Virgo Cluster using H.E.S.S. observations of M 87
Creators: name: Collaboration, H. E. S. S.
name: :
name: Aharonian, F.
name: Benkhali, F. Ait
name: Arcaro, C.
name: Aschersleben, J.
name: Backes, M.
name: Martins, V. Barbosa
name: Batzofin, R.
name: Becherini, Y.
name: Berge, D.
name: Bernlöhr, K.
name: Bi, B.
name: Böttcher, M.
name: Boisson, C.
name: Bolmont, J.
name: Borowska, J.
name: Bradascio, F.
name: Breuhaus, M.
name: Brose, R.
name: Brun, F.
name: Bruno, B.
name: Bulik, T.
name: Burger-Scheidlin, C.
name: Bylund, T.
name: Caroff, S.
name: Casanova, S.
name: Cecil, R.
name: Celic, J.
name: Cerruti, M.
name: Chand, T.
name: Chandra, S.
name: Chen, A.
name: Chibueze, J.
name: Chibueze, O.
name: Cotter, G.
name: Mbarubucyeye, J. Damascene
name: Djannati-Ataï, A.
name: Egberts, K.
name: Ernenwein, J. -P.
name: de Clairfontaine, G. Fichet
name: Filipovic, M.
name: Fontaine, G.
name: Füßling, M.
name: Funk, S.
name: Gabici, S.
name: Ghafourizadeh, S.
name: Giavitto, G.
name: Glawion, D.
name: Glicenstein, J. F.
name: Goswami, P.
name: Grolleron, G.
name: Grondin, M. -H.
name: Haerer, L.
name: Haupt, M.
name: Hermann, G.
name: Hinton, J. A.
name: Holch, T. L.
name: Horns, D.
name: Jamrozy, M.
name: Jankowsky, F.
name: Joshi, V.
name: Jung-Richardt, I.
name: Kasai, E.
name: Katarzyński, K.
name: Khatoon, R.
name: Khélifi, B.
name: Kluźniak, W.
name: Komin, Nu.
name: Kosack, K.
name: Kostunin, D.
name: Lang, R. G.
name: Stum, S. Le
name: Leitl, F.
name: Lemière, A.
name: Lemoine-Goumard, M.
name: Lenain, J. -P.
name: Leuschner, F.
name: Lohse, T.
name: Luashvili, A.
name: Lypova, I.
name: Mackey, J.
name: Malyshev, D.
name: Malyshev, D.
name: Marandon, V.
name: Marchegiani, P.
name: Marcowith, A.
name: Marinos, P.
name: Martí-Devesa, G.
name: Marx, R.
name: Meyer, M.
name: Mitchell, A.
name: Moderski, R.
name: Mohrmann, L.
name: Montanari, A.
name: Moulin, E.
name: Muller, J.
name: Nakashima, K.
name: de Naurois, M.
name: Niemiec, J.
name: Noel, A. Priyana
name: O'Brien, P.
name: Ohm, S.
name: Olivera-Nieto, L.
name: Wilhelmi, E. de Ona
name: Panny, S.
name: Panter, M.
name: Parsons, R. D.
name: Peron, G.
name: Pita, S.
name: Prokhorov, D. A.
name: Prokoph, H.
name: Pühlhofer, G.
name: Quirrenbach, A.
name: Reichherzer, P.
name: Reimer, A.
name: Reimer, O.
name: Renaud, M.
name: Rieger, F.
name: Rowell, G.
name: Rudak, B.
name: Velasco, E. Ruiz
name: Sahakian, V.
name: Salzmann, H.
name: Sanchez, D. A.
name: Santangelo, A.
name: Sasaki, M.
name: Schäfer, J.
name: Schüssler, F.
name: Schwanke, U.
name: Shapopi, J. N. S.
name: Sol, H.
name: Specovius, A.
name: Spencer, S.
name: Stawarz, Ł.
name: Steenkamp, R.
name: Steinmassl, S.
name: Steppa, C.
name: Sushch, I.
name: Suzuki, H.
name: Takahashi, T.
name: Tanaka, T.
name: Taylor, A. M.
name: Terrier, R.
name: Tsirou, M.
name: Tsuji, N.
name: Uchiyama, Y.
name: van Eldik, C.
name: van Soelen, B.
name: Vecchi, M.
name: Veh, J.
name: Venter, C.
name: Vink, J.
name: Wach, T.
name: Wagner, S. J.
name: White, R.
name: Wierzcholska, A.
name: Wong, Yu Wun
name: Zacharias, M.
name: Zargaryan, D.
name: Zdziarski, A. A.
name: Zech, A.
name: Zouari, S.
name: Żywucka, N.
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences
subject: FOS: Physical sciences

description: The origin of the gamma-ray emission from M87 is currently a matter of debate. This work aims to localize the VHE (100 GeV-100 TeV) gamma-ray emission from M87 and probe a potential extended hadronic emission component in the inner Virgo Cluster. The search for a steady and extended gamma-ray signal around M87 can constrain the cosmic-ray energy density and the pressure exerted by the cosmic rays onto the intra-cluster medium, and allow us to investigate the role of the cosmic rays in the active galactic nucleus feedback as a heating mechanism in the Virgo Cluster. H.E.S.S. telescopes are sensitive to VHE gamma rays and have been utilized to observe M87 since 2004. We utilized a Bayesian block analysis to identify M87 emission states with H.E.S.S. observations from 2004 until 2021, dividing them into low, intermediate, and high states. Because of the causality argument, an extended ($\gtrsim$kpc) signal is allowed only in steady emission states. Hence, we fitted the morphology of the 120h low state data and found no significant gamma-ray extension. Therefore, we derived for the low state an upper limit of 58"(corresponding to $\approx$4.6kpc) in the extension of a single-component morphological model described by a rotationally symmetric 2D Gaussian model at 99.7% confidence level. Our results exclude the radio lobes ($\approx$30 kpc) as the principal component of the VHE gamma-ray emission from the low state of M87. The gamma-ray emission is compatible with a single emission region at the radio core of M87. These results, with the help of two multiple-component models, constrain the maximum cosmic-ray to thermal pressure ratio $X_{CR,max.}$$\lesssim$$0.32$ and the total energy in cosmic-ray protons (CRp) to $U_{CR}$$\lesssim$5$\times10^{58}$ erg in the inner 20kpc of the Virgo Cluster for an assumed CRp power-law distribution in momentum with spectral index $α_{p}$=2.1.
description: 15 pages, 7 figures. Accepted for publication in A&amp;A. Corresponding authors: Victor Barbosa Martins, Stefan Ohm, Cornelia Arcaro, Natalia \.Zywucka, Mathieu de Naurois