Revisiting variable gamma-ray sky at 1 GeV with 6 years of Fermi-LAT
  data
  We perform a blind search for the variability of the gamma-ray sky in the
energy range E>1 GeV using 308 weeks of the Fermi-LAT data. We use the
technique based on the comparison of the weekly photon counts and exposures in
sky pixels by means of the Kolmogorov-Smirnov test. We consider the flux
variations in the region significant if statistical probability of uniformity
is less than $4\times10^{-6}$, which corresponds to 0.05 false detections in
the whole set of 12288 pixels. Close inspection of the detected variable
regions result in identification of 8 sources without previous known
variability. Two of them are included in the second Fermi LAT source catalogue
(FBQS J122424.1+243623 and GB6 J0043+3426) and one (3EG J1424+3734) was
reported by EGRET and also was included in the First Fermi LAT source catalogue
(1FGL), but is missing in the 2FGL. Possible identifications of five other
sources are obtained using NED and SIMBAD databases (1RXS J161939.9+765515, PMN
J2320-6447, PKS 0226-559, PKS J0030-0211, PMN J0225-2603). These new variable
gamma-ray sources demonstrate recurring flaring activity with time scale ~weeks
and have hard spectra. Their spectral energy distributions deviate
significantly from a simple power-law shape and often peak around ~GeV. These
properties of activity are typical for flaring blazars.
