ABSTRACT We report the Fermi Large Area Telescope (LAT) discovery of high-energy
(MeV/GeV) γ-ray emission positionally consistent with the center of the radio galaxy M87, at
a source significance of over 10σ in 10 months of all-sky survey data. Following the
detections of Cen A and Per A, this makes M87 the third radio galaxy seen with the LAT. The
faint point-like γ-ray source has a> 100 MeV flux of 2.45 (±0.63)× 10− 8 photons cm− 2 s− 1
(photon index= 2.26±0.13) with no significant variability detected within the LAT observation …

We present the high-energy (MeV-GeV) gamma-ray detection of the radio galaxy M87 with
the Fermi Large Area Telescope (LAT). The detection of M87 marks the third radio galaxy
seen by Fermi in addition to Cen A and Per A. The point-like source, which reached a
significance of> 10 sigma after 10 months of all-sky survey data, is positionally consistent
with the center of M87. Spectral analysis of the source resulted in a> 100 MeV flux of 2.5* 10-
8 ph cm-2 s-1, and a photon index of 2.3. Thus no significant flaring of the source is …