Fermi Large Area Telescope Third Source Catalog        Acero+, 2015)
  Version by Trushkin from FITS file with five columns
===========================================================================
We present the third Fermi Large Area Telescope source catalog (3FGL)
of sources in the 100 MeV-300 GeV range. Based on the first four years of
science data from the Fermi Gamma-ray Space Telescope mission, it is the
deepest yet in this energy range. Relative to the 2FGL catalog, the 3FGL
catalog incorporates twice as much data as well as a number of analysis
improvements, including improved calibrations at the event reconstruction
level, an updated model for Galactic diffuse gamma emission, a refined
procedure for source detection, and improved methods for associating
LAT sources with potential counterparts at other wavelengths. The 3FGL
catalog includes 3033 sources above 4-sigma significance, with source
location regions, spectral properties, and monthly light curves for
each. Of these, 78 are flagged as potentially being due to imperfections
in the model for Galactic diffuse emission. Twenty-five sources are
modeled explicitly as spatially extended, and overall 232 sources are
considered as identified based on angular extent or correlated variability
(periodic or otherwise) observed at other wavelengths. For 1009 sources
we have not found plausible counterparts at other wavelengths. More than
1100 of the identified or associated sources are active galaxies of
the blazar class; several other classes of non-blazar active galaxies
are also represented in the 3FGL. Pulsars represent the largest Galactic
source class. From source counts of Galactic sources we estimate the
contribution of unresolved sources to the Galactic diffuse emission is
3% at 1 GeV.