Fermi-lat discovery of gev gamma-ray emission from the young supernova remnant cassiopeia A
Number of Authors: 172
2010 (English)In: Astrophysical Journal Letters, ISSN 2041-8205, Vol. 710, no 1, L92-L97 p.Article in journal (Refereed) Published
We report on the first detection of GeV high-energy gamma-ray emission from a young supernova remnant (SNR) with the Large Area Telescope aboard the Fermi Gamma-ray Space Telescope. These observations reveal a source with no discernible spatial extension detected at a significance level of 12.2 sigma above 500 MeV a a location that is consistent with the position of the remnant of the supernova explosion that occurred around 1680 in the Cassiopeia constellation-Cassiopeia A (Cas A). The gamma-ray flux and spectral shape of the source are consistent with a scenario in which the gamma-ray emission originates from relativistic particles accelerated in the shell of this remnant. The total content of cosmic rays (electrons and protons) accelerated in Cas A can be estimated as W(CR) similar or equal to (1-4) x 10(49) erg thanks to the well-known density in the remnant assuming that the observed gamma ray originates in the SNR shell(s). The magnetic field in the radio-emitting plasma can be robustly constrained as B >= 0.1 mG, providing new evidence of the magnetic field amplification at the forward shock and the strong field in the shocked ejecta.
Place, publisher, year, edition, pages
2010. Vol. 710, no 1, L92-L97 p.
Acceleration of particles, ISM, individual objects (Cassiopeia A), Radiation mechanisms, non-thermal
Astronomy, Astrophysics and Cosmology
IdentifiersURN: urn:nbn:se:kth:diva-101213DOI: 10.1088/2041-8205/710/1/L92ISI: 000274438700020ScopusID: 2-s2.0-77749342903OAI: oai:DiVA.org:kth-101213DiVA: diva2:546786
QC 20120824. Author count: 1722012-08-242012-08-24Bibliographically approved