Very High Energy Gamma-Ray Emission from the Blazar Markarian 421
Abstract
Very high energy gamma-ray emission from the BL Lac object Markarian 421 has been detected over three observing seasons on 59 nights between April 1992 and June 1994 with the Whipple 10-meter imaging Cherenkov telescope. During its initial detection in 1992, its flux above 500 GeV was 1.610photons cm s. Observations in 1993 confirmed this level of emission. For observations made between December 1993 and April 1994, its intensity was a factor of 2.20.5 lower. Observations on 14 and 15 May, 1994 showed an increase over this quiescent level by a factor of 10 (Kerrick et al. 1995). This strong outburst suggests that 4 episodes of increased flux measurements on similar time scales in 1992 and 1994 may be attributed to somewhat weaker outbursts. The variability of the TeV gamma-ray emission from Markarian 421 stands in contrast to EGRET observations (Lin et al. 1994) which show no evidence for variability.
Cite
@article{arxiv.astro-ph/9602068,
title = {Very High Energy Gamma-Ray Emission from the Blazar Markarian 421},
author = {M. S. Schubnell and C. W. Akerlof and S. Biller J. Buckley and D. A. Carter-Lewis and M. F. Cawley and M. Chantell and V. Connaughton and D. J. Fegan and S. Fennell and J. A. Gaidos and A. M. Hillas and A. D. Kerrick R. C. Lamb and D. I. Meyer and G. Mohanty and J. Rose and A. C. Rovero and G. Sembroski and T. C. Weekes and C. Wilson and J. Zweerink},
journal= {arXiv preprint arXiv:astro-ph/9602068},
year = {2009}
}
Comments
gzip compressed tar file including LaTeX text and 4 postscript figures (14 pages total incl. 4 tables), accepted for publication in the Astrophysical Journal. Contact address is [email protected]