8th HEAD Meeting, 8-11 September, 2004
Session 4 Jets and Blazars
Poster, Wednesday, September 8, 2004, 9:00am-10:00pm

[Previous] | [Session 4] | [Next]

[4.04] Long Timescale Variability of Known TeV Emitting BL Lacs Using the Whipple Atmospheric Cherenkov Telescope

A. D. Falcone (Purdue University), VERITAS Collaboration

At this time, there are five significantly detected TeV gamma-ray emitting active galactic nuclei (AGN) that can be observed by the Whipple Observatory. All of these objects, Mrk421, Mrk501, 1ES1959+650, 1ES2344+514 and H1426+428, are high frequency peaked BL Lacs that exhibit strong variability at X-ray and TeV energies. The characteristics of the gamma-ray emission process/es for these objects is still not well understood. Various hadronic and inverse Compton models can be used to explain the emission, and there is very little understanding of the intrinsic differences between high and low emission states. Many studies have been done in the past on individual objects during short timescales, usually during a major outburst of emission. The Whipple Observatory 10-meter imaging atmospheric Cherenkov gamma-ray telescope has been operating in a relatively stable state with a single camera since 1999. Monitoring data from 1999-2004 can be used to study the variability characteristics of these sources on timescales ranging from ~10 minutes to years. By characterizing the variability of emission on several objects over long time periods, we can attempt to determine the nature of the gamma-ray emission process/es and constrain parameters of the local AGN environment.

The author(s) of this abstract have provided an email address for comments about the abstract: afalcone@egret.sao.arizona.edu

[Previous] | [Session 4] | [Next]

Bulletin of the American Astronomical Society, 36 #3
© 2004. The American Astronomical Soceity.