The far emission region of the γ-ray blazar PKS B1424-418.
Abstract
We report multiwavelength (infrared-optical, ultraviolet, X-ray and γ-ray) data from the flat spectrum radio quasar (FSRQ) PKS B1424-418 (z = 1.52) gathered during an active phase in 2013 April. As for a few other cases of FSRQs reported in literature, the detection by the Large Area Telescope on board Fermi of γ-rays with energy above 10 GeV indicates that the emission likely occurs beyond the highly opaque (τ ∼ 10) broad-line region. This conclusion is strengthened by a model fit to the spectral energy distribution, which allows us to locate the emission region even beyond the distance generally assumed for the dusty torus. The consequent large size (∼1 pc) inferred for the emission region cannot account for the observed daily-scale variability of the γ-ray flux. We discuss the possibility that short-term variability results from fast magnetic reconnection events, as proposed in recent works.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- August 2013
- DOI:
- 10.1093/mnrasl/slt087
- arXiv:
- arXiv:1306.0734
- Bibcode:
- 2013MNRAS.435L..24T
- Keywords:
-
- radiation mechanisms: non-thermal;
- galaxies: jets;
- gamma-rays: galaxies;
- Astrophysics - High Energy Astrophysical Phenomena
- E-Print:
- 5 pages, 3 figures, accepted for publication in MNRAS Letters