On the July 2007 flare of the blazar 3C 454.3

TL;DR

This paper analyzes a significant gamma-ray and optical flare of blazar 3C 454.3 in July 2007, revealing correlated spectral energy distribution changes and confirming jet behavior models.

Contribution

It provides the first simultaneous multi-wavelength spectral energy distribution of 3C 454.3 during the 2007 flare, linking optical, UV, X-ray, and gamma-ray observations.

Findings

Gamma-ray flux increased while optical/X-ray flux decreased.

Confirmed jet behavior models with multi-wavelength data.

Compared 2007 flare with previous 2005 observations.

Abstract

In July 2007, 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, that 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, UV, X-ray and gamma-ray data. These shows that an increased gamma-ray flux is accompanied by a weaker optical/X-ray flux with respect to the flare observed in the Spring 2005 by INTEGRAL and Swift. This confirms earlier suggestions about the behaviour of the jet of 3C 454.3.