Discovery of Powerful Gamma-Ray Flares from the Crab Nebula
Abstract
The well-known Crab Nebula is at the center of the SN1054 supernova remnant. It consists of a rotationally powered pulsar interacting with a surrounding nebula through a relativistic particle wind. The emissions originating from the pulsar and nebula have been considered to be essentially stable. Here, we report the detection of strong gamma-ray (100 mega-electron volts to 10 giga-electron volts) flares observed by the AGILE satellite in September 2010 and October 2007. In both cases, the total gamma-ray flux increased by a factor of three compared with the non-flaring flux. The flare luminosity and short time scale favor an origin near the pulsar, and we discuss Chandra Observatory x-ray and Hubble Space Telescope optical follow-up observations of the nebula. Our observations challenge standard models of nebular emission and require power-law acceleration by shock-driven plasma wave turbulence within an approximately 1-day time scale.
- Publication:
-
Science
- Pub Date:
- February 2011
- DOI:
- 10.1126/science.1200083
- arXiv:
- arXiv:1101.2311
- Bibcode:
- 2011Sci...331..736T
- Keywords:
-
- ASTRONOMY;
- Astrophysics - High Energy Astrophysical Phenomena
- E-Print:
- 23 pages (including Supporting On-line Material), 8 figures, 1 table. Version published in Science Express on January 6, 2011 (available at http://www.sciencemag.org/content/early/2011/01/05/science.1200083)