Short Timescale Gamma-ray Variability of Blazars and EGRET Unidentified Objects

Session 39 - AGNs, QSOs, Active Galaxies.
Display session, Wednesday, June 11
South Main Hall,

[39.08] Short Timescale Gamma-ray Variability of Blazars and EGRET Unidentified Objects

S. D. Bloom, D. J. Thompson, R. C. Hartman (NASA/GSFC), C. von Montigny (Landessternwarte Heidelberg-Konigstuhl)

Previous studies of blazars and unidentified objects observed by EGRET have shown strong evidence for variability over a timescale of months and years. In addition, several extraordinary blazars are known to vary in gamma-rays over several days, and possibly within a day. For the first time, we are conducting a systematic search for short timescale variability over the entire EGRET database available for general public use. This paper will focus on the first results for blazars and high-galactic latitude unidentified sources. A preliminary analysis of the EGRET gamma-ray data from 30 viewing periods shows that several sources may be variable on short timescales. The best case can be made for the BL Lac object 0521-365, which appears to have had a 1-2 day flare during July 1994. The quasar PKS 0208-512 and the unidentified object 2EG 1835+592 also display possible varibility on 2 day timescales.

The author(s) of this abstract have provided an email address for comments about the abstract: bloom@egret.gsfc.nasa.gov

Program listing for Wednesday