A Search for Fast X-Ray Variability from Active Galactic Nuclei Using Swift
Abstract
Blazars are a class of active galactic nuclei (AGNs) known for their very rapid variabilty in the high energy regions of the electromagnetic spectrum. Despite this known fast variability, X-ray observations have generally not revealed variability in blazars with rate doubling or halving timescales less than approximately 15 minutes. Since its launch, the Swift X-ray Telescope has obtained 0.2-10 keV X-ray data on 143 AGNs, including blazars, through intense target of opportunity observations that can be analyzed in a multiwavelength context and used to model jet parameters, particularly during flare states. We have analyzed this broad Swift data set in a search for short timescale variability in blazars that could limit the size of the emission region in the blazar jet. While we do find several low-significance possible flares with potential indications of rapid variability, we find no strong evidence for rapid (<15 minutes) doubling or halving times in flares in the soft X-ray energy band for the AGNs analyzed.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- March 2015
- DOI:
- 10.1088/0004-637X/802/1/33
- arXiv:
- arXiv:1501.07288
- Bibcode:
- 2015ApJ...802...33P
- Keywords:
-
- acceleration of particles;
- galaxies: active;
- galaxies: jets;
- gamma rays: general;
- X-rays: general;
- Astrophysics - High Energy Astrophysical Phenomena
- E-Print:
- Accepted for publication in the Astrophysical Journal, 8 pages, 3 figures