GeV outburst in Mrk501

P. Sreekumar

D. Bertsch, R. Hartman, D. Thompson

S. Bloom

Y. Lin

G. Kanbach

R. Mukerjee


Mrk501 has recently been detected at GeV energies (Kataoka et al. 1999), making it the 3rd TeV blazar with a known GeV component. Previous multiwavelength campaigns showed well correlated outburts at x-ray and TeV energies; however no significant changes were observed in the mean GeV emission. We present here new evidence for GeV outburts in Mrk501. The photon spectrum appears to be extremely hard compared to the typical GeV blazar. Further, this outbursts appears uncorrelated with enhanced emission at x-ray energies. The resulting spectral energy distribution (SED) during the outburst suggests a cutoff in the high-energy emission beyond a few hundred GeV. We discuss compatibility of the Mrk501 SED with current theoretical models on blazar emission.

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On 16 Jul 1999, 09:19.