Publication

Rapid tev gamma-ray flaring of bl lacertae

Arlen, T.
Aune, T.
Beilicke, M.
Benbow, W.
Bouvier, A.
Buckley, J. H.
Bugaev, V.
Cesarini, A.
Ciupik, L.
Connolly, M. P.
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Citation
Arlen, T. Aune, T.; Beilicke, M.; Benbow, W.; Bouvier, A.; Buckley, J. H.; Bugaev, V.; Cesarini, A.; Ciupik, L.; Connolly, M. P.; Cui, W.; Dickherber, R.; Dumm, J.; Errando, M.; Falcone, A.; Federici, S.; Feng, Q.; Finley, J. P.; Finnegan, G.; Fortson, L.; Furniss, A.; Galante, N.; Gall, D.; Griffin, S.; Grube, J.; Gyuk, G.; Hanna, D.; Holder, J.; Humensky, T. B.; Kaaret, P.; Karlsson, N.; Kertzman, M.; Khassen, Y.; Kieda, D.; Krawczynski, H.; Krennrich, F.; Maier, G.; Moriarty, P.; Mukherjee, R.; Nelson, T.; O'Faoláin de Bhróithe, A.; Ong, R. A.; Orr, M.; Park, N.; Perkins, J. S.; Pichel, A.; Pohl, M.; Prokoph, H.; Quinn, J.; Ragan, K.; Reyes, L. C.; Reynolds, P. T.; Roache, E.; Saxon, D. B.; Schroedter, M.; Sembroski, G. H.; Staszak, D.; Telezhinsky, I.; Tešić, G.; Theiling, M.; Tsurusaki, K.; Varlotta, A.; Vincent, S.; Wakely, S. P.; Weekes, T. C.; Weinstein, A.; Welsing, R.; Williams, D. A.; Zitzer, B.; Jorstad, S. G.; MacDonald, N. R.; Marscher, A. P.; Smith, P. S.; Walker, R. C.; Hovatta, T.; Richards, J.; Max-Moerbeck, W.; Readhead, A.; Lister, M. L.; Kovalev, Y. Y.; Pushkarev, A. B.; Gurwell, M. A.; Lähteenmäki, A.; Nieppola, E.; Tornikoski, M.; Järvelä, E.; , (2012). Rapid tev gamma-ray flaring of bl lacertae. The Astrophysical Journal 762 (2),
Abstract
We report on the detection of a very rapid TeV gamma-ray flare from BL Lacertae on 2011 June 28 with the Very Energetic Radiation Imaging Telescope Array System (VERITAS). The flaring activity was observed during a 34.6 minute exposure, when the integral flux above 200 GeV reached (3.4 +/- 0.6) x 10(-6) photons m(-2) s(-1), roughly 125% of the Crab Nebula flux measured by VERITAS. The light curve indicates that the observations missed the rising phase of the flare but covered a significant portion of the decaying phase. The exponential decay time was determined to be 13 +/- 4 minutes, making it one of the most rapid gamma-ray flares seen from a TeV blazar. The gamma-ray spectrum of BL Lacertae during the flare was soft, with a photon index of 3.6 +/- 0.4, which is in agreement with the measurement made previously by MAGIC in a lower flaring state. Contemporaneous radio observations of the source with the Very Long Baseline Array revealed the emergence of a new, superluminal component from the core around the time of the TeV gamma-ray flare, accompanied by changes in the optical polarization angle. Changes in flux also appear to have occurred at optical, UV, and GeV gamma-ray wavelengths at the time of the flare, although they are difficult to quantify precisely due to sparse coverage. A strong flare was seen at radio wavelengths roughly four months later, which might be related to the gamma-ray flaring activities. We discuss the implications of these multiwavelength results.
Funder
Publisher
IOP Publishing
Publisher DOI
10.1088/0004-637x/762/2/92
Rights
Attribution-NonCommercial-NoDerivs 3.0 Ireland