Gamma-Ray Flares from the Crab Nebula
2011 (English)In: Science, ISSN 0036-8075, Vol. 331, no 6018, 739-742 p.Article in journal (Refereed) Published
A young and energetic pulsar powers the well-known Crab Nebula. Here, we describe two separate gamma-ray (photon energy greater than 100 mega-electron volts) flares from this source detected by the Large Area Telescope on board the Fermi Gamma-ray Space Telescope. The first flare occurred in February 2009 and lasted approximately 16 days. The second flare was detected in September 2010 and lasted approximately 4 days. During these outbursts, the gamma-ray flux from the nebula increased by factors of four and six, respectively. The brevity of the flares implies that the gamma rays were emitted via synchrotron radiation from peta-electron-volt (10(15) electron volts) electrons in a region smaller than 1.4 x 10(-2) parsecs. These are the highest-energy particles that can be associated with a discrete astronomical source, and they pose challenges to particle acceleration theory.
Place, publisher, year, edition, pages
2011. Vol. 331, no 6018, 739-742 p.
IdentifiersURN: urn:nbn:se:su:diva-67516DOI: 10.1126/science.1199705ISI: 000287205700062OAI: oai:DiVA.org:su-67516DiVA: diva2:470329
authorCount :1682011-12-282011-12-282011-12-28Bibliographically approved