On the 2007 July flare of the blazar 3C 454.3

Abstract

In 2007 July, the blazar 3C 454.3 underwent a flare in the optical, reaching R ~ 13 on July 19. Then the optical flux decreased by one magnitude, being R ~ 14 when the source was detected by the gamma-ray satellite AGILE, which observed the source on July 24-30. At the same time, the Swift satellite performed a series of snapshots. We can construct the simultaneous spectral energy distribution using optical, ultraviolet, X-ray and gamma-ray data. These show that an increased gamma-ray flux is accompanied by a weaker optical/X-ray flux with respect to the flare observed in the spring of 2005 by INTEGRAL and Swift. This confirms earlier suggestions about the behaviour of the jet of 3C 454.3. © 2007 The Authors. Journal compilation © 2007 RAS.