1302.3388 (Hugh Dickinson et al.)

Discovery of transient high-energy gamma-ray emission from the BL Lacertae object 5C 3.178    [PDF]

Hugh Dickinson, Christian Farnier

We report the discovery of transient, point-like high energy gamma-ray emission coincident with the position of the suspected BL Lac object 5C 3.178. The source was detected using the Fermi Large Area Telescope (LAT) at a significance level of ~8 sigma during a 200 day period which began on MJD 55882. The observed gamma-ray emission is characterised by a moderate 0.2-300 GeV flux F(0.2-300 GeV)=$(8.22\pm2.04)\times10^{-9}$ ph cm$^{-2}$s$^{-1}$ and a hard power law spectrum with spectral index $\Gamma=1.76\pm0.09$. These properties appear consistent with the known sub-population of TeV gamma-ray-emitting BL Lac objects, implying that the source may be detectable using atmospheric Cherenkov telescope arrays.

View original: http://arxiv.org/abs/1302.3388