The NRAO VLA Sky Survey
Session 64 -- AGN Surveys and High Energy Spectra
Oral presentation, Thursday, January 13, 2:15-3:45, Salon IV Room (Crystal Gateway)

## [64.02] The NRAO VLA Sky Survey

J. J. Condon, W. D. Cotton, E. W. Greisen, R. A. Perley, Q. F. Yin (NRAO), J. J. Broderick (VPI\&SU)

\noindent The NRAO VLA Sky Survey (NVSS) is mapping the entire sky north of $\delta = -40\deg$ at $\nu = 1.4$\thinspace GHz. A grid of over $2\times10^5$ partially overlapping snapshot maps will be mosaiced to yield sets of 2326 $4\deg \times 4\deg$ corrected sky images in each of the Stokes parameters I, Q, and U with $\theta = 45''$ FWHM resolution and a nearly uniform $6\sigma$ detection limit $S_{\rm P} \approx 2$\thinspace mJy\thinspace beam$^{-1} \approx 0.6$\thinspace K. These images should contain about $2\times10^6$ extragalactic sources, including luminous radio galaxies and quasars, most of the galaxies found by IRAS at $\lambda = 60\thinspace\mu$m, ultraluminous starburst galaxies and protogalaxies even at cosmological distances, as well as statistically useful numbers $N \gg \sqrt{N}$ of nearby ($z \ll 1$) normal galaxies and low-luminosity AGN. Their rms position uncertainties will range from $<1''$ for $S > 10$\thinspace mJy to $\approx 5''$ at $S=2$\thinspace mJy.

\noindent The NVSS is being made as a service to the astronomical community. We claim no proprietary rights to either the raw data or the finished products because we believe that the full scientific potential of such a large survey will not be realized until all astronomers can use it. The principal data products will be the $4\deg\times4\deg$ mosaiced images in FITS format plus ASCII tables of discrete source parameters. They will be released via anonymous ftp (ftp 192.33.115.53, login anonymous, password = your name, cd vlass) as soon as they are made. To guarantee equal access for all users, we will use only those images that have been placed in this open directory for our own research.

\noindent The NRAO is operated by Associated Universities, Inc., under cooperative agreement with the National Science Foundation.