The first gamma-ray detection of the narrow-line Seyfert 1 FBQS
  J1644+2619
  We report the discovery of gamma-ray emission from the narrow-line Seyfert 1
(NLSy1) galaxy FBQS J1644+2619 by the Large Area Telescope on board the Fermi
satellite. The Third Fermi LAT Source catalogue reports an unidentified
gamma-ray source, detected over the first four years of Fermi operation, 0.23
deg from the radio position of the NLSy1. Analysing 76 months of gamma-ray data
(2008 August 4 - 2014 December 31) we are able to better constrain the
localization of the gamma-ray source. The new position of the gamma-ray source
is 0.05 deg from FBQS J1644+2619, suggesting a spatial association with the
NLSy1. This is the sixth NLSy1 detected at high significance by Fermi-LAT so
far. Notably, a significant increase of activity was observed in gamma-rays
from FBQS J1644+2619 during 2012 July-October, and an increase of activity in
V-band was detected by the Catalina Real-Time Sky Survey in the same period.
