The first gamma-ray detection of the narrow-line Seyfert 1 FBQS J1644+2619

TL;DR

This paper reports the first gamma-ray detection of the narrow-line Seyfert 1 galaxy FBQS J1644+2619, revealing its high-energy activity and spatial association with gamma-ray emission, expanding the understanding of NLSy1 galaxies.

Contribution

First gamma-ray detection of FBQS J1644+2619, confirming NLSy1 galaxies as gamma-ray emitters and providing precise localization of the source.

Findings

Gamma-ray emission detected from FBQS J1644+2619.

Spatial association between gamma-ray source and NLSy1 galaxy.

Significant gamma-ray activity increase in mid-2012.

Abstract

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.