9. Scientific Impact of the Survey

The most important discoveries that have been made using the POSS - quasars, starburst galaxies, the large-scale structure of the Universe - were not anticipated by those who carried out the original survey. And many of these discoveries have come as a result of comparing work done at other wavelengths with this unparalleled optical database. Likewise, we cannot anticipate all of the new source classes and astrophysical insights that the FIRST survey will yield, but we are confident that cross-correlation of the maps and catalogs we produce with data from other wavelength regimes will be enormously productive. To maximize the utility of the survey, it has been designed to cover the same square degrees of sky as the Sloan Digital Sky Survey (SDSS) which will, by the end of the decade, have produced five-color CCD images of this entire area to and will be in the process of collecting spectra from of the objects therein. The subarcsecond positions our survey will produce will allow immediate optical identification of of our radio catalog from the SDSS database, further enhancing its utility. While an exhaustive description of the scientific impact this project will have is beyond the scope of this paper, a few examples of areas in which the FIRST survey will make fundamental contributions include:

the evolution of radio-loud quasars from a complete, flux-limited sample of 20,000 such objects brighter than ;

quasar absorption line studies from the sample of several hundred new quasars brighter than ;

the bivariate X-ray-radio luminosity function for BL Lacs through an increase in the sample of known BL Lacs by a factor of via cross-correlation with ROSAT catalogs;

unified models of AGN, in that complete flux-limited samples of all classes of active nuclei (Seyferts, BL Lacs, OVVs, radio galaxies, and quasars) with to members each will emerge from the comparison of this survey with the SDSS AGN sample;

the evolution of the intracluster medium of galaxy clusters through the identification of large samples of distant clusters using head-tail and bent-jet radio sources as tracers;

the evolution of large-scale structure through the use of complete flux-limited samples of radio galaxies and/or starburst galaxies discovered in the survey, as well as the statistics of the radio source spatial distribution and cross-correlation with microwave background fluctuation studies;

gravitational lenses, by discovering radio arcs, lensed radio galaxy lobes, and multiple point sources through the use of various optical filters;

galaxy evolution from a variety of perspectives including the followup of high redshift, steep spectrum radio galaxies, and the identification of objects such as IRAS 10214+4724 (a source below the NVSS threshold) from comparison with IRAS and ISO samples;

the discovery of nearby millisecond and normal pulsar candidates through the identification of steep spectrum objects using the Texas and WENNS catalogs in the first wide-area survey unbiased with respect to low duty cycles, high dispersion measures, short periods, and large binary accelerations;

through the comparison of large stellar catalogs directly with the maps, the first radio-selected samples of stars with a flux density limit of 0.5 mJy for use in such diverse applications as the identification of nearby, coeval moving groups of red dwarfs and the prevalence of magnetically active coronae on all late-type stars;

the inevitable new phenomena that emerge when one addresses such a large region of hitherto unexplored parameter space.