Unveiling extended gamma-ray emission around HESS J1813-178
Creators: name: Aharonian, F.
name: Benkhali, F. Ait
name: Aschersleben, J.
name: Ashkar, H.
name: Backes, M.
name: Baktash, A.
name: Martins, V. Barbosa
name: Barnard, J.
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: de Lavergne, M. de Bony
name: Borowska, J.
name: Bouyahiaoui, M.
name: Breuhaus, M.
name: Brose, R.
name: Brun, F.
name: Bruno, B.
name: Bulik, T.
name: Burger-Scheidlin, C.
name: Caroff, S.
name: Casanova, S.
name: Cecil, R.
name: Celic, J.
name: Cerruti, M.
name: Chambery, P.
name: Chand, T.
name: Chen, A.
name: Chibueze, J.
name: Chibueze, O.
name: Cotter, G.
name: Mbarubucyeye, J. Damascene
name: Djannati-Ataï, A.
name: Dmytriiev, A.
name: Doroshenko, V.
name: Einecke, S.
name: Ernenwein, J. -P.
name: Feijen, K.
name: Filipovic, M.
name: Fontaine, G.
name: Füßling, M.
name: Funk, S.
name: Gabici, S.
name: Gallant, Y. A.
name: Ghafourizadeh, S.
name: Giavitt, G.
name: Glawion, D.
name: Glicenstein, J. F.
name: Goswami, P.
name: Grolleron, G.
name: Grondin, M. -H.
name: Hinton, J. A.
name: Hofmann, W.
name: Holch, T. L.
name: Holler, M.
name: Jamrozy, M.
name: Jankowsky, F.
name: Joshi, V.
name: Jung-Richardt, I.
name: Katarzyński, K.
name: Khatoon, R.
name: Khélifi, B.
name: Klepser, S.
name: Kluźniak, W.
name: Komin, Nu.
name: Kosack, K.
name: Kostunin, D.
name: Kundu, A.
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: Mackey, J.
name: Malyshev, D.
name: Malyshev, D.
name: Marandon, V.
name: Marinos, P.
name: Martí-Devesa, G.
name: Marx, R.
name: Mehta, A.
name: Mitchell, A.
name: Moderski, R.
name: Mohrmann, L.
name: Montanari, A.
name: Moulin, E.
name: Murach, T.
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: Ostrowski, M.
name: Panny, S.
name: Panter, M.
name: Parsons, R. D.
name: Prokhorov, D. A.
name: Pühlhofer, G.
name: Punch, M.
name: Quirrenbach, A.
name: Regeard, M.
name: Reichherzer, P.
name: Reimer, A.
name: Reimer, O.
name: Ren, H.
name: Renaud, M.
name: Reville, B.
name: Rieger, F.
name: Roellinghoff, G.
name: Rudak, B.
name: Sahakian, V.
name: Salzmann, H.
name: Sasaki, M.
name: Schüssler, F.
name: Schutte, H. M.
name: Shapopi, J. N. S.
name: Specovius, A.
name: Spencer, S.
name: Steenkamp, R.
name: Steinmassl, S.
name: Steppa, C.
name: Sushch, I.
name: Suzuki, H.
name: Takahashi, T.
name: Tanaka, T.
name: Terrier, R.
name: Tluczykont, M.
name: Tsuji, N.
name: Unbehaun, T.
name: van Eldik, C.
name: Vecchi, M.
name: Veh, J.
name: Venter, C.
name: Vink, J.
name: Wach, T.
name: Wagner, S. J.
name: Wierzcholska, A.
name: Zacharias, M.
name: Zargaryan, D.
name: Zdziarski, A. A.
name: Zouari, S.
name: Żywucka, N.
Publisher: name: arXiv
Year: 2024
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences
subject: FOS: Physical sciences

description: HESS J1813$-$178 is a very-high-energy $γ$-ray source spatially coincident with the young and energetic pulsar PSR J1813$-$1749 and thought to be associated with its pulsar wind nebula (PWN). Recently, evidence for extended high-energy emission in the vicinity of the pulsar has been revealed in the Fermi Large Area Telescope (LAT) data. This motivates revisiting the HESS J1813$-$178 region, taking advantage of improved analysis methods and an extended data set. Using data taken by the High Energy Stereoscopic System (H.E.S.S.) experiment and the Fermi-LAT, we aim to describe the $γ$-ray emission in the region with a consistent model, to provide insights into its origin. We performed a likelihood-based analysis on 32 hours of H.E.S.S. data and 12 years of Fermi-LAT data and fit a spectro-morphological model to the combined datasets. These results allowed us to develop a physical model for the origin of the observed $γ$-ray emission in the region. In addition to the compact very-high-energy $γ$-ray emission centered on the pulsar, we find a significant yet previously undetected component along the Galactic plane. With Fermi-LAT data, we confirm extended high-energy emission consistent with the position and elongation of the extended emission observed with H.E.S.S. These results establish a consistent description of the emission in the region from GeV energies to several tens of TeV. This study suggests that HESS J1813$-$178 is associated with a $γ$-ray PWN powered by PSR J1813$-$1749. A possible origin of the extended emission component is inverse Compton emission from electrons and positrons that have escaped the confines of the pulsar and form a halo around the PWN.
description: 13+5 pages, 13+11 figures. Accepted for publication in A&amp;A. Corresponding authors: T.Wach, A.Mitchell, V.Joshi, P.Chamb\'ery