Gaidos, J.A. and Akerlof, C.W. and Biller, S.D. and Boyle, P.J. and Breslin, A.C. and Buckley, J.H. and Carter-Lewis, D.A. and Catanese, M. and Cawley, Michael F. and Fegan, D.J. and Finley, J.P. and Bussons Gordo, J. and Hillas, A.M. and Krennrich, F. and Lamb, R.C. and Lessard, R.W. and McEnery, J.E. and Masterson, C. and Mohanty, G. and Moriarty, P. and Quinn, J. and Rodgers, A.J. and Rose, H.J. and Samuelson, F.W. and Schubnell, M.S. and Sembroski, G.H. and Srinivasan, R. and Weekes, T.C. and Wilson, C.L. and Zweerink, J. (1996) Extremely rapid bursts of TeV photons from the Active Galaxy Markarian 421. Nature, 383. pp. 319-320. ISSN 1476-4687

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Abstract

DISCRETE astronomical sources of photons in the TeV energy range are believed to be associated with regions in the relativistic outflow of particles and radiation from compact objects, such as neutron stars and black holes. The flux from such sources, together with the timescales on which they vary, can provide strong constraints on the emission mechanisms. Here we report the observation of two dramatic outbursts of TeV photons from the active galaxy Markarian 421 (Mrk421). In the first outburst, which had a doubling time of about one hour, the flux increased above the relatively quiescent value by more than a factor of 50, briefly making Mrk421 the brightest TeV source in the sky. In the second outburst, which lasted approximately 30 minutes, the flux increased by a factor of 20–25. These data suggest that the emission region is extremely small—perhaps even smaller than our Solar System. This could prove challenging for current theoretical models of such emissions.

Item Type:	Article
Keywords:	Gamma-Ray Sources; Relativistic Jets; X-Ray; Emission; Blazars;
Academic Unit:	Faculty of Science and Engineering > Experimental Physics
Item ID:	12613
Identification Number:	https://doi.org/10.1038/383319a0
Depositing User:	Dr. Michael Cawley
Date Deposited:	25 Mar 2020 12:00
Journal or Publication Title:	Nature
Publisher:	Nature Publishing Group
Refereed:	Yes
URI:	Publisher
Use Licence:	This item is available under a Creative Commons Attribution Non Commercial Share Alike Licence (CC BY-NC-SA). Details of this licence are available here

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