Discovery of Gamma-ray Emission from M31 via FERMI-LAT
arXiv:1008.2537 · doi:10.1063/1.3629489
Abstract
2 years worth of archival FERMI-LAT data was used to search for the gamma-ray emission from the Andromeda galaxy. The data show no noticeable elliptical image. Subsequent on-off source aperture photometry analysis using a CO image template show a 7 sigma excess in the number of on-source apertures in comparison to the off-source apertures, yielding a flux of (4.95+/-0.71)x10-8 photons cm-2 s-1 for E>100 MeV.
arXiv comment7 pages, 5 figures