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 h 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 tithe-averaged flux from Markarian 421 over this period was 0.446 + - 0.008 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. (C) 2013 Elsevier B.V. All rights reserved.
| Original language | English (Ireland) |
|---|---|
| Pages (from-to) | 1-10 |
| Number of pages | 10 |
| Journal | Astroparticle Physics |
| Volume | 54 |
| DOIs | |
| Publication status | Published - 1 Feb 2014 |
Keywords
- AGN
- Markarian 421
- TeV gamma rays
Authors (Note for portal: view the doc link for the full list of authors)
- Authors
- Acciari, VA,Arlen, T,Aune, T,Benbow, W,Bird, R,Bouvier, A,Bradbury, SM,Buckley, JH,Bugaev, V,Perez, ID,Carter-Lewis, DA,Cesarini, A,Ciupik, L,Collins-Hughes, E,Connolly, MP,Cui, W,Duke, C,Dumm, J,Falcone, A,Federici, S,Fegan, DJ,Fegan, SJ,Finley, JP,Finnegan, G,Fortson, L,Gaidos, J,Galante, N,Gall, D,Gibbs, K,Gillanders, GH,Griffin, S,Grube, J,Gyuk, G,Hanna, D,Horan, D,Humensky, TB,Kaaret, P,Kertzman, M,Khassen, Y,Kieda, D,Krawczynski, H,Krennrich, F,Lang, MJ,McEnery, JE,Madhavan, AS,Moriarty, P,Nelson, T,de Bhroithe, AO,Ong, RA,Orr, M,Otte, AN,Perkins, JS,Petry, D,Pichel, A,Pohl, M,Quinn, J,Ragan, K,Reynolds, T,Roache, E,Rovero, A,Schroedter, M,Sembroski, GH,Smith, A,Telezhinsky, I,Theiling, M,Toner, J,Tyler, J,Varlotta, A,Vivier, M,Wakely, SP,Ward, JE,Weekes, TC,Weinstein, A,Welsing, R,