Discovery of VHE \(\gamma\)-ray emission from the SNR G54.1+0.3

• Published in: arXiv.org 2010-07
• Main Authors: Acciari, V A, Aliu, E, Arlen, T, Aune, T, Bautista, M, Beilicke, M, Benbow, W, Boltuch, D, Bradbury, S M, Buckley, J H, Bugaev, V, Butt, Y, Byrum, K, Cesarini, A, Ciupik, L, Cui, W, Dickherber, R, Duke, C, Finley, J P, Finnegan, G, tson, L, Furniss, A, Galante, N, Gall, D, Gillanders, G H, Godambe, S, Gotthelf, E V, Grube, J, Guenette, R, Gyuk, G, Hanna, D, Holder, J, Hui, C M, Humensky, T B, Imran, A, Kaaret, P, Karlsson, N, Kertzman, M, Kieda, D, Konopelko, A, Krawczynski, H, Krennrich, F, Lang, M J, LeBohec, S, Maier, G, McArthur, S, McCann, A, McCutcheon, M, Moriarty, P, Muhkerjee, R, Ong, R A, Otte, A N, Pandel, D, Perkins, J S, Pohl, M, Quinn, J, Ragan, K, Reyes, L C, Reynolds, P T, Roache, E, Rose, H J, Schroedter, M, Sembroski, G H, Senturk, G Demet, Slane, P, Smith, A W, Steele, D, Swordy, S P, Těsić, G, Theiling, M, Thibadeau, S, Vassiliev, V V, Vincent, S, Wakely, S P, Ward, J E, Weekes, T C, Weinstein, A, Weisgarber, T, Williams, D A, Wissel, S, Wood, M, Zitzer, B
• Format: Article
• Language: English
• Subjects: Crab nebula; Emission; Energy spectra; Gamma rays; Ground-based observation; Luminosity; Morphology; Nebulae; Pulsars
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.1005.0032

We report the discovery of very high energy gamma-ray emission from the direction of the SNR G54.1+0.3 using the VERITAS ground-based gamma-ray observatory. The TeV signal has an overall significance of 6.8\(\sigma\) and appears point-like given the 5\(^{arcminute}\) resolution of the instrument. The integral flux above 1 TeV is 2.5% of the Crab Nebula flux and significant emission is measured between 250 GeV and 4 TeV, well described by a power-law energy spectrum dN/dE \(\sim\) E\(^{-\Gamma}\) with a photon index \(\Gamma= 2.39\pm0.23_{stat}\pm0.30_{sys}\). We find no evidence of time variability among observations spanning almost two years. Based on the location, the morphology, the measured spectrum, the lack of variability and a comparison with similar systems previously detected in the TeV band, the most likely counterpart of this new VHE gamma-ray source is the PWN in the SNR G54.1+0.3. The measured X-ray to VHE gamma-ray luminosity ratio is the lowest among all the nebulae supposedly driven by young rotation-powered pulsars, which could indicate a particle-dominated PWN.