A1 Refereed original research article in a scientific journal
MAGIC detection of short-term variability of the high-peaked BL Lac object 1ES 0806+524
Authors: J. Aleksić, S. Ansoldi, L. A. Antonelli, P. Antoranz, A. Babic, P. Bangale, J. A. Barrio, J. Becerra González, W. Bednarek, E. Bernardini, B. Biasuzzi, A. Biland, O. Blanch, S. Bonnefoy, G. Bonnoli, F. Borracci, T. Bretz,†, E. Carmona, A. Carosi, P. Colin, E. Colombo, J. L. Contreras, J. Cortina, S. Covino, P. Da Vela, F. Dazzi, A. De Angelis, G. De Caneva, B. De Lotto, E. de Oña Wilhelmi, C. Delgado Mendez, F. Di Pierro, D. Dominis Prester, D. Dorner, M. Doro, S. Einecke, D. Eisenacher, D. Elsaesser, A. Fernández-Barral, D. Fidalgo, M. V. Fonseca, L. Font, K. Frantzen, C. Fruck, D. Galindo, R. J. García López, M. Garczarczyk, D. Garrido Terrats, M. Gaug, N. Godinović, A. González Muñoz, S. R. Gozzini, D. Hadasch, Y. Hanabata, M. Hayashida, J. Herrera, J. Hose, D. Hrupec, W. Idec, V. Kadenius, H. Kellermann, M. L. Knoetig, K. Kodani, Y. Konno, J. Krause, H. Kubo, J. Kushida, A. La Barbera, D. Lelas, N. Lewandowska, E. Lindfors, S. Lombardi, F. Longo, M. López, R. López-Coto, A. López-Oramas, E. Lorenz, I. Lozano, M. Makariev, K. Mallot, G. Maneva, K. Mannheim, L. Maraschi, B. Marcote, M. Mariotti, M. Martínez, D. Mazin, U. Menzel, J. M. Miranda, R. Mirzoyan, A. Moralejo, P. Munar-Adrover, D. Nakajima, V. Neustroev, A. Niedzwiecki, M. Nievas Rosillo, K. Nilsson, K. Nishijima, K. Noda, R. Orito, A. Overkemping, S. Paiano, M. Palatiello, D. Paneque, R. Paoletti, J. M. Paredes, X. Paredes-Fortuny, M. Persic, J. Poutanen, P. G. Prada Moroni, E. Prandini, I. Puljak, R. Reinthal, W. Rhode, M. Ribó, J. Rico, J. Rodriguez Garcia, T. Saito, K. Saito, K. Satalecka, V. Scalzotto, V. Scapin, C. Schultz, T. Schweizer, S. N. Shore, A. Sillanpää, J. Sitarek, I. Snidaric, D. Sobczynska, A. Stamerra, T. Steinbring, M. Strzys, L. Takalo, H. Takami, F. Tavecchio, P. Temnikov, T. Terzić, D. Tescaro, M. Teshima, J. Thaele, D. F. Torres, T. Toyama, A. Treves, P. Vogler, M. Will, R. Zanin, K. Berger, S. Buson, F. D'Ammando, D. Gasparrini, T. Hovatta, W. Max-Moerbeck, A. Readhead, J. Richards
Publisher: OXFORD UNIV PRESS
Publication year: 2015
Journal: Monthly Notices of the Royal Astronomical Society
Journal name in source: MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
Journal acronym: MON NOT R ASTRON SOC
Volume: 451
Issue: 1
First page : 739
Last page: 750
Number of pages: 12
ISSN: 0035-8711
DOI: https://doi.org/10.1093/mnras/stv895(external)
Web address : http://arxiv.org/abs/1504.06115(external)
The high-frequency-peaked BL Lac (HBL) 1ES 0806+524 (z = 0.138) was discovered in very high energy (VHE) gamma-rays in 2008. Until now, the broad-band spectrum of lES 0806+524 has been only poorly characterized, in particular at high energies. We analysed multiwave-length observations from gamma-rays to radio performed from 2011 January to March, which were triggered by the high activity detected at optical frequencies. These observations constitute the most precise determination of the broad-band emission of ES 0806+524 to date. The stereoscopic Major Atmospheric Gamma-Ray Imaging Cherenkov (MAGIC) observations yielded a gamma-ray signal above 250 GeV of (3.7 +/- 0.7) per cent of the Crab Nebula flux with a statistical significance of 9.9a. The multiwavelength observations showed significant variability in essentially all energy bands, including a VHE gamma-ray flare that lasted less than one night, which provided unprecedented evidence for short-term variability in lES 0806+524. The spectrum of this flare is well described by a power law with a photon index of 2.97 +/- 0.29 between similar to 150 GeV and 1 TeV and an integral flux of (9.3 +/- 1.9) per cent of the Crab nebula flux above 250 GeV. The spectrum during the non-flaring VHE activity is compatible with the only available VHE observation performed in 2008 with VERITAS when the source was in a low optical state. The broad-band spectral energy distribution can be described with a one-zone synchrotron self-Compton model with parameters typical for HBLs, indicating that lES 0806+524 is not substantially different from the HBLs previously detected.
Downloadable publication This is an electronic reprint of the original article. |  |
