Observation of Markarian 421 in TeV gamma rays over a 14-year time span
Abstract
The variability of the blazar Markarian 421 in TeV gamma rays over a 14-year time period has been explored with the Whipple 10 m telescope. It is shown that the dynamic range of its flux variations is large and similar to that in X-rays. A correlation between the X-ray and TeV energy bands is observed during some bright flares and when the complete data sets are binned on long timescales. The main database consists of 878.4 hours of observation with the Whipple telescope, spread over 783 nights. The peak energy response of the telescope was 400 GeV with 20% uncertainty. This is the largest database of any TeV-emitting active galactic nucleus (AGN) and hence was used to explore the variability profile of Markarian 421. The time-averaged flux from Markarian 421 over this period was 0.4460.008 Crab flux units. The flux exceeded 10 Crab flux units on three separate occasions. For the 2000-2001 season the average flux reached 1.86 Crab units, while in the 1996-1997 season the average flux was only 0.23 Crab units.
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Cite
@article{arxiv.1310.8150,
title = {Observation of Markarian 421 in TeV gamma rays over a 14-year time span},
author = {V. A. Acciari and T. Arlen and T. Aune and W. Benbow and R. Bird and A. Bouvier and S. M. Bradbury and J. H. Buckley and V. Bugaev and I. de la Calle Perez and D. A. Carter-Lewis and A. Cesarini and L. Ciupik and E. Collins-Hughes and M. P. Connolly and W. Cui and C. Duke and J. Dumm and A. Falcone and S. Federici and D. J. Fegan and S. J. Fegan and J. P. Finley and G. Finnegan and L. Fortson and J. Gaidos and N. Galante and D. Gall and K. Gibbs and G. H. Gillanders and S. Griffin and J. Grube and G. Gyuk and D. Hanna and D. Horan and T. B. Humensky and P. Kaaret and M. Kertzman and Y. Khassen and D. Kieda and H. Krawczynski and F. Krennrich and M. J. Lang and J. E. McEnery and A. S. Madhavan and P. Moriarty and T. Nelson and A. O'Faoláin de Bhróithe and R. A. Ong and M. Orr and A. N. Otte and J. S. Perkins and D. Petry and A. Pichel and M. Pohl and J. Quinn and K. Ragan and P. T. Reynolds and E. Roache and A. Rovero and M. Schroedter and G. H. Sembroski and A. Smith and I. Telezhinsky and M. Theiling and J. Toner and J. Tyler and A. Varlotta and M. Vivier and S. P. Wakely and J. E. Ward and T. C. Weekes and A. Weinstein and R. Welsing and D. A. Williams and S. Wissel},
journal= {arXiv preprint arXiv:1310.8150},
year = {2015}
}
Comments
29 pages, 15 figures. Accepted for publication in Astroparticle Physics