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arXiv · astro-ph/0701868

X-ray/UV/Optical follow-up of the blazar PKS 2155-304 after the giant TeV flares of July 2006

L. Foschini·G. Ghisellini·F. Tavecchio·A. Treves·L. Maraschi·M. Gliozzi·C. M. Raiteri·M. Villata·E. Pian·G. Tagliaferri·G. Tosti·R. M. Sambruna·G. Malaguti·G. Di Cocco·P. Giommi
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Abstract

We present all the publicly available data, from optical/UV wavelengths (UVOT) to X-rays (XRT, BAT), obtained from Swift observations of the blazar PKS 2155-304, performed in response to the rapid alert sent out after the strong TeV activity (up to 17 Crab flux level at E > 200 GeV) at the end of July 2006. The X-ray flux increased by a factor of 5 in the 0.3-10 keV energy band and by a factor of 1.5 at optical/UV wavelengths, with roughly one day of delay. The comparison of the spectral energy distribution built with data quasi-simultaneous to the TeV detections shows an increase of the overall normalization with respect to archival data, but only a small shift of the frequency of the synchrotron peak that remains consistent with the values reported in past observations when the TeV activity was much weaker.

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L. Foschini, G. Ghisellini, F. Tavecchio, A. Treves, L. Maraschi, M. Gliozzi, C. M. Raiteri, M. Villata, E. Pian, G. Tagliaferri, G. Tosti, R. M. Sambruna, G. Malaguti, G. Di Cocco, P. Giommi. 2007-01-30. X-ray/UV/Optical follow-up of the blazar PKS 2155-304 after the giant TeV flares of July 2006. https://doi.org/10.1086/513271

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