Previous abstract Next abstract
We describe work on identifying optical counterparts to radio sources detected at 1.4 GHz as part of the FIRST and NVSS radio surveys being conducted with the VLA. The optical catalog is taken from POSS~I and POSS~II copy plates digitized with the APS machine at Minnesota. Counterparts are being sought for a preliminary catalog of $\sim 28000$ FIRST radio sources contained in a declination strip running through the NGP. In addition, a catalog of $\sim 14000$ sources at the NCP from the NVSS has been compiled and used to find optical counterparts. From a statistical analysis of positional matches we determine the limiting optical flux for reliable counterpart identification on POSS~I and POSS~II. Optical and radio morphology, along with optical colors, are used in an effort to sort the matched sources into the two canonical radio source populations, i.e., actively star-forming galaxies and ``monsters.'' Further subdivision is attempted in order to differentiate radio QSO's (and lesser AGN) from giant elliptical galaxies. The issue of uniformity in the optical identifications is addressed by examination of the positional matching and flux limits as a function of position on the POSS~I and POSS~II plates.
Monday program listing