Very-High-Energy \(\gamma\)-Ray Observations of the Blazar 1ES 2344+514 with VERITAS

• Published in: arXiv.org 2017-08
• Main Authors: Allen, C, Archambault, S, Archer, A, Benbow, W, Bird, R, Bourbeau, E, Brose, R, Buchovecky, M, Buckley, J H, Bugaev, V, Cardenzana, J V, Cerruti, M, Chen, X, Christiansen, J L, Connolly, M P, Cui, W, Daniel, M K, Eisch, J D, Falcone, A, Feng, Q, Fernandez-Alonso, M, Finley, J P, Fleischhack, H, Flinders, A, tson, L, Furniss, A, Gillanders, G H, Griffin, S, Grube, J, Hütten, M, Håkansson, N, Hanna, D, Hervet, O, Holder, J, Hughes, G, Humensky, T B, Johnson, C A, Kaaret, P, Kar, P, Kelley-Hoskins, N, Kertzman, M, Kieda, D, Krause, M, Krennrich, F, Kumar, S, Lang, M J, Maier, G, McArthur, S, McCann, A, Meagher, K, Moriarty, P, Mukherjee, R, Nguyen, T, Nieto, D, O'Brien, S, A O'Faoláin de Bhróithe, Ong, R A, Otte, A N, Park, N, Petrashyk, A, Pichel, A, Pohl, M, Popkow, A, Pueschel, E, Quinn, J, Ragan, K, Reynolds, P T, Richards, G T, Roache, E, Rovero, A C, Rulten, C, Sadeh, I, Santander, M, Sembroski, G H, Shahinyan, K, Telezhinsky, I, Tucci, J V, Tyler, J, Wakely, S P, Weinstein, A, Wilhelm, A, Williams, D A
• Format: Article
• Language: English
• Subjects: Attenuation; BL Lacertae objects; Emission spectra; Light curve; Power law
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.1708.02829

We present very-high-energy \(\gamma\)-ray observations of the BL Lac object 1ES 2344+514 taken by the Very Energetic Radiation Imaging Telescope Array System (VERITAS) between 2007 and 2015. 1ES 2344+514 is detected with a statistical significance above background of \(20.8\sigma\) in \(47.2\) hours (livetime) of observations, making this the most comprehensive very-high-energy study of 1ES 2344+514 to date. Using these observations the temporal properties of 1ES 2344+514 are studied on short and long times scales. We fit a constant flux model to nightly- and seasonally-binned light curves and apply a fractional variability test, to determine the stability of the source on different timescales. We reject the constant-flux model for the 2007-2008 and 2014-2015 nightly-binned light curves and for the long-term seasonally-binned light curve at the \(> 3\sigma\) level. The spectra of the time-averaged emission before and after correction for attenuation by the extragalactic background light are obtained. The observed time-averaged spectrum above 200 GeV is satisfactorily fitted (\({\chi^2/NDF = 7.89/6}\)) by a power-law function with index \(\Gamma = 2.46 \pm 0.06_{stat} \pm 0.20_{sys} \) and extends to at least 8 TeV. The extragalactic-background-light-deabsorbed spectrum is adequately fit (\({\chi^2/NDF = 6.73/6}\)) by a power-law function with index \(\Gamma = 2.15 \pm 0.06_{stat} \pm 0.20_{sys} \) while an F-test indicates that the power-law with exponential cutoff function provides a marginally-better fit (\(\chi^2/NDF \) = \(2.56 / 5 \)) at the 2.1\(\sigma\) level. The source location is found to be consistent with the published radio location and its spatial extent is consistent with a point source.