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A comparison of AGN detected at gamma ray energies by EGRET with flat-spectrum radio sources observed in surveys for intraday variability reveals that a remarkably high fraction of EGRET blazars show significant interstellar scintillation at centimetre wavelengths. Scintillating AGN will therefore be targets of interest for GLAST, scheduled for launch in early 2008. We suggest that the variable, scintillating flat-spectrum radio source PMN J1326-5256 is associated with the unidentified EGRET source 3EG J1316-5244. We describe the properties of PMN J1326-5256 and present recent results of monitoring with the ATCA and Ceduna radio telescopes.
Active galactic nuclei are the most luminous persistent (non-transient, even if often variable) objects in the Universe. They are bright in the entire electromagnetic spectrum. Blazars are a special class where the jets point nearly to our line of si
Recent Fermi-Large Area Telescope (LAT) light curves indicate an active $gamma$-ray state spanning about five months from 2016 June to 2016 October in the BL Lac object 1749+096 (OT 081). During this period, we find two notable $gamma$-ray events: an
About one third of the gamma-ray sources listed in the second Fermi LAT catalog (2FGL) have no firmly established counterpart at lower energies so being classified as unidentified gamma-ray sources (UGSs). Here we propose a new approach to find candi
PKS 2155-304 is a blazar located in the Southern Hemisphere, monitored with the High Energy Stereoscopic System (H.E.S.S.) at very high energy (VHE, E>100 GeV) $gamma$ rays every year since 2002. Thanks to the large data set collected in the VHE rang
According to the second Fermi LAT Catalog (2FGL), about one third of the gamma-ray sources listed have no assigned counterparts at lower energies. Many statistical methods have been developed to find proper counterparts for these sources. We explore