학술논문

An intermittent extreme BL Lac: MWL study of 1ES 2344+514 in an enhanced state
Document Type
Working Paper
Author
MAGIC CollaborationAcciari, V. A.Ansoldi, S.Antonelli, L. A.Engels, A. ArbetBaack, D.Babić, A.Banerjee, B.de Almeida, U. BarresBarrio, J. A.González, J. BecerraBednarek, W.Bellizzi, L.Bernardini, E.Berti, A.Besenrieder, J.Bhattacharyya, W.Bigongiari, C.Blanch, O.Bonnoli, G.Bošnjak, Ž.Busetto, G.Carosi, R.Ceribella, G.Cerruti, M.Chai, Y.Chilingarian, A.Cikota, S.Colak, S. M.Colin, U.Colombo, E.Contreras, J. L.Cortina, J.Covino, S.D'Elia, V.Da Vela, P.Dazzi, F.De Angelis, A.De Lotto, B.Delfino, M.Delgado, J.Depaoli, D.Di Pierro, F.Di Venere, L.Espiñeira, E. Do SoutoPrester, D. DominisDonini, A.Doro, M.Elsaesser, D.Ramazani, V. FallahFattorini, A.Ferrara, G.Foffano, L.Fonseca, M. V.Font, L.Fruck, C.Fukami, S.López, R. J. GarcíaGarczarczyk, M.Gasparyan, S.Gaug, M.Giglietto, N.Giordano, F.Gliwny, P.Godinović, N.Green, D.Hadasch, D.Hahn, A.Herrera, J.Hoang, J.Hrupec, D.Hütten, M.Inada, T.Inoue, S.Ishio, K.Iwamura, Y.Jouvin, L.Kajiwara, Y.Kerszberg, D.Kobayashi, Y.Kubo, H.Kushida, J.Lamastra, A.Lelas, D.Leone, F.Lindfors, E.Lombardi, S.Longo, F.López, M.López-Coto, R.López-Oramas, A.Loporchio, S.Fraga, B. Machado de OliveiraMaggio, C.Majumdar, P.Makariev, M.Mallamaci, M.Maneva, G.Manganaro, M.Maraschi, L.Mariotti, M.Martínez, M.Mazin, D.Mender, S.Mićanović, S.Miceli, D.Miener, T.Minev, M.Miranda, J. M.Mirzoyan, R.Molina, E.Moralejo, A.Morcuende, D.Moreno, V.Moretti, E.Munar-Adrover, P.Neustroev, V.Nigro, C.Nilsson, K.Ninci, D.Nishijima, K.Noda, K.Nogués, L.Nozaki, S.Ohtani, Y.Oka, T.Otero-Santos, J.Paiano, S.Palatiello, M.Paneque, D.Paoletti, R.Paredes, J. M.Pavletić, L.Peñil, P.Peresano, M.Persic, M.Moroni, P. G. PradaPrandini, E.Puljak, I.Ribó, M.Rico, J.Righi, C.Rugliancich, A.Saha, L.Sahakyan, N.Saito, T.Sakurai, S.Satalecka, K.Schleicher, B.Schmidt, K.Schweizer, T.Sitarek, J.Šnidarić, I.Sobczynska, D.Spolon, A.Stamerra, A.Strom, D.Strzys, M.Suda, Y.Surić, T.Takahashi, M.Tavecchio, F.Temnikov, P.Terzić, T.Teshima, M.Torres-Albà, N.Tosti, L.van Scherpenberg, J.Vanzo, G.Acosta, M. VazquezVentura, S.Verguilov, V.Vigorito, C. F.Vitale, V.Vovk, I.Will, M.Zarić, D.Collaboration, FACTBalbo, M.Beck, M.Biederbeck, N.Biland, A.Blank, M.Bretz, T.Bruegge, K.Bulinski, M.Buss, J.Doerr, M.Dorner, D.Hildebrand, D.Iotov, R.Klinger, M.Mannheim, K.Mueller, S. AchimNeise, D.Neronov, A.Nöthe, M.Paravac, A.Rhode, W.Sedlaczek, K.Shukla, A.Sliusar, V.Tani, L.Theissen, F.Walter, R.Collaborators, MWLPulido, J. AcostaFilippenko, A. V.Hovatta, T.Kiehlmann, S.Larionov, V. M.Max-Moerbeck, W.Raiteri, C. M.Readhead, A. C. S.Šegon, M.Villata, M.Zheng, W.
Source
MNRAS 496, 3912 (2020)
Subject
Astrophysics - High Energy Astrophysical Phenomena
Language
Abstract
Extreme High-frequency BL~Lacs (EHBL) feature their synchrotron peak of the broadband spectral energy distribution (SED) at $\nu_{\rm s} \geq $10$^{17}$\,Hz. The BL~Lac object 1ES~2344+514 was included in the EHBL family because of its impressive shift of the synchrotron peak in 1996. During the following years, the source appeared to be in a low state without showing any extreme behaviours. In August 2016, 1ES~2344+514 was detected with the ground-based $\gamma$-ray telescope FACT during a high $\gamma$-ray state, triggering multi-wavelength (MWL) observations. We studied the MWL light curves of 1ES~2344+514 during the 2016 flaring state, using data from radio to VHE $\gamma$ rays taken with OVRO, KAIT, KVA, NOT, some telescopes of the GASP-WEBT collaboration at the Teide, Crimean, and St. Petersburg observatories, \textit{Swift}-UVOT, \textit{Swift}-XRT, \textit{Fermi}-LAT, FACT and MAGIC. With simultaneous observations of the flare, we built the broadband SED and studied it in the framework of a leptonic and an hadronic model. The VHE $\gamma$-ray observations show a flux level of 55\% of the Crab Nebula flux above 300\,GeV, similar to the historical maximum of 1995. The combination of MAGIC and \textit{Fermi}-LAT spectra provides an unprecedented characterization of the inverse-Compton peak for this object during a flaring episode. The $\Gamma$ index of the intrinsic spectrum in the VHE $\gamma$-ray band is $2.04\pm0.12_{\rm stat}\pm0.15_{\rm sys}$. We find the source in an extreme state with a shift of the position of the synchrotron peak to frequencies above or equal to $10^{18}$\,Hz
Comment: Accepted in MNRAS. Corresponding authors: M. Manganaro, A. Arbet Engels, D. Dorner