An intermittent extreme BL Lac: MWL study of 1ES 2344+514 in an enhanced state. Issue 3 (17th June 2020)

• Record Type: Journal Article
• Authors: Acciari, MAGIC Collaboration: V A; Ansoldi, S; Antonelli, L A; Arbet Engels, A; Babić, A; Banerjee, B; Barres de Almeida, U; Barrio, J A; Becerra González, J; Bednarek, 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; Chilingaryan, 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; Do Souto Espiñeira, E; Dominis Prester, D; Donini, A; Doro, M; Elsaesser, D; Fallah Ramazani, V; Fattorini, A; Ferrara, G; Foffano, L; Fonseca, M V; Font, L; Fruck, C; Fukami, S; García López, R J; Garczarczyk, M; Gasparyan, S; Gaug, M; Giglietto, N; Giordano, F; Godinović, N; Gliwny, P; 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; Machado de Oliveira Fraga, B; Maggio, 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; Prada Moroni, P G; Prandini, 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; Vazquez Acosta, M; Ventura, S; Verguilov, V; Vigorito, C F; Vitale, V; Vovk, I; Will, M; Zarić, D; Baack, FACT Collaboration: D; Balbo, 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; Achim Mueller, S; Neise, D; Neronov, A; Nöthe, M; Paravac, A; Rhode, W; Schleicher, B; Sedlaczek, K; Shukla, A; Sliusar, V; Tani, L; Theissen, F; Walter, R; Acosta Pulido, MWL Collaborators: J; Filippenko, 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;
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 496:Issue 3(2020)
• Page Start: 3912
• Page End: 3928
• Publication Date: 2020-06-17
• Subjects: galaxies: active -- BL Lacertae objects: individual: 1ES 2344+514 -- gamma-rays: galaxies; Astronomy -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnras/staa1702
• Languages: English
• ISSNs: 0035-8711

Abstract

ABSTRACT: Extreme high-frequency BL Lacs (EHBL) feature their synchrotron peak of the broad-band spectral energy distribution (SED) at νs ≥ 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 2016 August, 1ES 2344+514 was detected with the ground-based γ-ray telescope FACT during a high γ-ray state, triggering multiwavelength (MWL) observations. We studied the MWL light curves of 1ES 2344+514 during the 2016 flaring state, using data from radio to very-high-energy (VHE) γ-rays taken with OVRO, KAIT, KVA, NOT, some telescopes of the GASP-WEBT collaboration at the Teide, Crimean, and St. Petersburg observatories, Swift -UVOT, Swift -XRT, Fermi -LAT, FACT, and MAGIC. With simultaneous observations of the flare, we built the broad-band SED and studied it in the framework of a leptonic and a hadronic model. The VHE γ-ray observations show a flux level of 55 per cent of the Crab Nebula flux above 300 GeV, similar to the historical maximum of 1995. The combination of MAGIC and Fermi -LAT spectra provides an unprecedented characterization of the inverse-Compton peak for this object during a flaring episode. The Γ index of the intrinsic spectrum in the VHE γ-ray band is 2.04 ± 0.12stat ± 0.15sys . 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.