Multiwavelength Observations of a TeV-Flare from W Comae
Pian, E.; Costa, E.; Cucchiara, A.; Mereghetti, S.; Barbiellini, G.; Fortin, P.; Longo, F.; Morselli, A.; Chen, A. W.; Colafrancesco, S.; Giommi, P.; Reyes, L. C.; Villata, M.; Di Cocco, G.; Aune, T.; Benbow, W.; Bugaev, V.; Cui, W.; Falcone, A.; Finley, J. P.; Fortson, L.; Furniss, A.; Grube, J.; Hanna, D.; Holder, J.; Humensky, T. B.; Kaaret, P.; Kertzman, M.; Kieda, D.; Lang, M. J.; Maier, G.; McArthur, S.; Moriarty, P.; Ong, R. A.; Otte, A. N.; Pandel, D.; Pohl, M.; Quinn, J.; Ragan, K.; Reynolds, P. T.; Roache, E.; Sembroski, G. H.; Vassiliev, V. V.; Wakely, S. P.; Ward, J. E.; Weinstein, A.; Williams, D. A.; Raiteri, C. M.; Pellizzoni, A.; Pilia, M.; Romano, P.; Nesci, R.; Beilicke, M.; Konopelko, A.; Larionov, V. M.; Arkharov, A. A.; Kurtanidze, O. M.; Böttcher, M.; Gianotti, F.; Mommert, M.; Feroci, M.; Galante, N.; Aliu, E.; Leto, P.; Aller, H. D.; Aller, M. F.; D'Ammando, F.; Perkins, J. S.; Wood, M.; Del Monte, E.; Donnarumma, I.; Evangelista, Y.; Krawczynski, H.; Soffitta, P.; Trois, A.; Buckley, J. H.; Ciupik, L.; McCann, A.; Lindfors, E.; Nilsson, K.; de la Calle Perez, I.; Vercellone, S.; Efimova, N. V.; Pacciani, L.; Verrecchia, F.; Vittorini, V.; Tavani, M.; Bulgarelli, A.; Giuliani, A.; Pucella, G.; Argan, A.; Caraveo, P.; Cattaneo, P. W.; De Paris, G.; Fiorini, M.; Fuschino, F.; Galli, M.; Labanti, C.; Lapshov, I.; Lazzarotto, F.; Lipari, P.; Marisaldi, M.; Morelli, E.; Perotti, F.; Piano, G.; Picozza, P.; Prest, M.; Rapisarda, M.; Rappoldi, A.; Rubini, A.; Sabatini, S.; Trifoglio, M.; Vallazza, E.; Zanello, D.; Pittori, C.; Santolamazza, P.; Salotti, L.; Heidt, J.; Cesarini, A.; Cannon, A.; Berdyugin, A.; Pursimo, T.; Acciari, V. A.; Dickherber, R.; Duke, C.; Gall, D.; Gillanders, G. H.; Gyuk, G.; Karlsson, N.; Krennrich, F.; Smith, A. W.; Theiling, M.; Thibadeau, S.; Varlotta, A.; Vincent, S.; Weekes, T. C.; Zambra, A.; Dultzin, D.; Pasanen, M.; Hiriart, D.; Cocco, V.; Froysland, T.; Millis, J.; Mastropietro, M.; Porrovecchio, G.; Ligustri, R.; Mujica, R.; Hui, C. M.; Bradbury, S. M.; Cogan, P.; Rose, H. J.; Steele, D.; Byrum, K.; Benitez, E.; Lahteenmaki, A.; Pichel, A.; Boltuch, D.; Gibbs, K.; Guenette, R.; Le Bohec, S.; McCutcheon, M.; Weisgarber, T.; Wissel, S.; Frutti, M.; Tetradze, S. D.; Kotiranta, M.; Lopez, J. M.; Sorcia, M.
United States, United Kingdom, Ireland, Canada, Argentina, Italy, Germany, Russia, Finland, Spain, Mexico
Abstract
We report results from an intensive multiwavelength campaign on the intermediate-frequency-peaked BL Lacertae object W Com (z = 0.102) during a strong outburst of very high energy gamma-ray emission in 2008 June. The very high energy gamma-ray signal was detected by VERITAS on 2008 June 7-8 with a flux F(>200 GeV) =(5.7 ± 0.6) × 10-11 cm-2 s-1, about three times brighter than during the discovery of gamma-ray emission from W Com by VERITAS in 2008 March. The initial detection of this flare by VERITAS at energies above 200 GeV was followed by observations in high-energy gamma rays (AGILE; E γ>= 100 MeV), X-rays (Swift and XMM-Newton), and at UV, and ground-based optical and radio monitoring through the GASP-WEBT consortium and other observatories. Here we describe the multiwavelength data and derive the spectral energy distribution of the source from contemporaneous data taken throughout the flare.