SBS 0846+513: a new gamma-ray emitting Narrow-Line Seyfert 1 galaxy

TL;DR

This paper reports the discovery of gamma-ray emission from SBS 0846+513, a Narrow-Line Seyfert 1 galaxy, revealing blazar-like relativistic jets and variability, suggesting it is a young blazar with a powerful jet.

Contribution

First detection of gamma-ray flaring activity and relativistic jets in SBS 0846+513, a Narrow-Line Seyfert 1 galaxy, indicating blazar-like properties.

Findings

Detected a gamma-ray flare with luminosity of 1.0x10^48 erg/s.

Inferred superluminal jet velocity of (8.2+/-1.5)c.

Observed blazar-like variability and spectral properties.

Abstract

We report Fermi-LAT observations of the radio-loud AGN SBS 0846+513 (z=0.5835), optically classified as a Narrow-Line Seyfert 1 galaxy, together with new and archival radio-to-X-ray data. The source was not active at gamma-ray energies during the first two years of Fermi operation. A significant increase in activity was observed during 2010 October-2011 August. In particular a strong gamma-ray flare was observed in 2011 June reaching an isotropic gamma-ray luminosity (0.1-300 GeV) of 1.0x10^48 erg/s, comparable to that of the brightest flat spectrum radio quasars, and showing spectral evolution in gamma rays. An apparent superluminal velocity of (8.2+/-1.5)c in the jet was inferred from 2011-2012 VLBA images, suggesting the presence of a highly relativistic jet. Both the power released by this object during the flaring activity and the apparent superluminal velocity are strong indications of the presence of a relativistic jet as powerful as those of blazars. In addition, variability and spectral properties in radio and gamma-ray bands indicate blazar-like behaviour, suggesting that, except for some distinct optical characteristics, SBS 0846+513 could be considered as a young blazar at the low end of the blazar's black hole mass distribution.