A Northern Survey of Gamma‐Ray Blazar Candidates

In preparation for GLAST, we have compiled a sample of blazar candidates toincrease the pool of well studied AGN from which GLAST counterparts will bedrawn. Sources were selected with our Figure of Merit (FoM) ranking; thus, theyhave radio and X-ray properties very similar to the EGRET blazars.Spectroscopic confirmation of these candidates is in progress, and more than70% of these objects have been identified as flat spectrum radio quasars and BLLac objects. We present ~250 new optical blazar identifications based onMcDonald Observatory spectroscopy, 224 with redshifts. Of these, 167 are in ourFoM-selected set. To motivate the Gamma-ray nature of these objects, we analyzed the currentrelease of the EGRET data for possible point sources at their radio positions.We develop two distinct methods to combine multiple EGRET observations of a skyposition into a single detection significance. We report a detection of thesignal of the set of blazar candidates in the EGRET data at the > 3 sigma levelby both techniques. We predict that the majority of these blazar candidateswill be found by GLAST due to its increased sensitivity, duty cycle andresolving power.Comment: ApJ Accepted (to appear 10 June 2005