The MAGIC Collaboration, F. Longo, F. Lucarelli, C. Pittori, S. Vercellone, for the AGILE team, D. Bastieri, C. Sbarra for the Fermi-LAT team, E. Angelakis, L. Fuhrmann, I. Nestoras, T. P. Krichbaum, A. Sievers, J. A. Zensus for the F-GAMMA team, K. A. Antonyuk, W. Baumgartner, A. Berduygin, M. Carini, K. Cook, N. Gehrels, M. Kadler, Yu. A. Kovalev, Y. Y. Kovalev, F. Krauss, H. A. Krimm, A. Lähteenmäki, M. L. Lister, W. Max-Moerbeck, M. Pasanen, A. B. Pushkarev, A. C. S. Readhead, J. L. Richards, J. Sainio, D. N. Shakhovskoy, K. V. Sokolovsky, M. Tornikoski, J. Tueller, M. Weidinger, J. Wilms
[Abridged] Context. To construct and interpret the spectral energy distribution (SED) of BL Lacertae objects, simultaneous broad-band observations are mandatory. Aims. We intend to study the simultaneous broad-band emission of the high-frequency peaked BL Lac object and known TeV emitter 1ES 2344+514 by means of a pre-organised multi-wavelength campaign independently of the current flux state. By correlating the obtained light curves and describing the corresponding SEDs with state-of-the-art models we intend to derive physical parameters of the emission region. Methods. The observations were conducted during simultaneous visibility windows of MAGIC and AGILE in late 2008. The measurements were complemented by Mets\"ahovi, RATAN-600, KVA+Tuorla, Swift and VLBA pointings. Additional coverage was provided by the ongoing long-term F-GAMMA and MOJAVE programs, the OVRO 40-m and CrAO telescopes as well as the Fermi satellite. The obtained SEDs are modelled using a one-zone as well as a self-consistent two-zone synchrotron self-Compton model. Results. 1ES 2344+514 is found at very low flux states in both X-rays and very high energy gamma rays. Variability is detected in the low frequency radio and X-ray bands only, where for the latter a small flare was observed. The X-ray flare was potentially caused by shock acceleration characterised by similar cooling and acceleration time scales. MOJAVE VLBA monitoring reveals a static jet whose components are stable over time scales of eleven years, opposite to previous findings. A significant correlation between the 15.0 GHz and the R-band monitoring light curves cannot be established. The observations presented here constitute the first multi-wavelength campaign on 1ES 2344+514 from radio to VHE energies and one of the few simultaneous SEDs during low activity states. The quasi-simultaneous Fermi-LAT data poses some challenges for SED modelling.
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http://arxiv.org/abs/1211.2608
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