Long duration variability of mrk 421

A. J. Smith, A. A. Abdo, B. Allen, D. Berley, S. Casanova, C. Chen, D. G. Coyne, B. L. Dingus, R. W. Ellsworth, L. Fleysher, R. Fleysher, M. M. Gonzalez, J. A. Goodman, E. Hays, C. M. Hoffman, B. Hopper, P. H. Hüntemeyer, B. E. Kolterman, C. P. Lansdell, J. T. LinnemannJ. E. Mcenery, A. I. Mincer, P. Nemethy, D. Noyes, J. M. Ryan, P. M. Saz Parkinson, A. Shoup, G. Sinnis, G. W. Sullivan, V. Vasileiou, G. P. Walker, D. A. Williams, X. W. Xu, G. B. Yodh

Research output: Contribution to conferencePaperpeer-review


Active Galaxies such as Mrk 421 have been shown to be highly variable at all time scales. Atmospheric Cherenkov Telescopes (ACTs) have excellent instantaneous sensitivity and have observed short bright flares from Mrk 421. However, long duration variability is difficult to monitor with ACTs due to their intermittent exposure. Milagro, in contrast, monitorsMrk 421 with daily observations. While Milagro lacks the sensitivity to detect short duration flares unless they are i extremely bright, it is well suited to make long duration monitoring of the total flux of Mrk 421 on time scales from months to years. In this paper we present the long duration variability and total fluence of Mrk 421 using 6 years of data from Milagro.

Original languageEnglish (US)
Number of pages4
StatePublished - 2007
Externally publishedYes
Event30th International Cosmic Ray Conference, ICRC 2007 - Merida, Yucatan, Mexico
Duration: Jul 3 2007Jul 11 2007


Other30th International Cosmic Ray Conference, ICRC 2007
CityMerida, Yucatan

ASJC Scopus subject areas

  • Nuclear and High Energy Physics


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