Published in The Astronomy and Astrophysics Review, Volume 18, Issue 1-2, pp. 1-65, 2010.
astro-ph/0908.1896

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RADIO AND MILLIMETER CONTINUUM SURVEYS AND THEIR ASTROPHYSICAL IMPLICATIONS

Gianfranco De Zotti ^{1, 2}, Marcella Massardi ^1,
2, Mattia Negrello ³ and Jasper Wall ⁴

¹ INAF - Osservatorio Astronomico di Padova, Vicolo dell'Osservatorio 5, I-35122 Padova, Italy
Email: gianfranco.dezotti@oapd.inaf.it
² SISSA/ISAS, Via Beirut 2-4, I-34014 Trieste, Italy
Tel.: +39-049-8293444, Fax: +39-049-8759840
Email: marcella.massardi@oapd.inaf.it
³ Department of Physics and Astronomy, Open University, Walton Hall, Milton Keynes MK7 6AA, United Kingdom
Email: m.negrello@open.ac.uk
⁴ Department of Physics and Astrophysics, University of British Columbia, Vancouver, Canada V6T 1Z1
Email: jvw@astro.ubc.ca

Abstract. We review the statistical properties of the main populations of radio sources, as emerging from radio and millimeter sky surveys. Recent determinations of local luminosity functions are presented and compared with earlier estimates still in widespread use. A number of unresolved issues are discussed. These include: the (possibly luminosity-dependent) decline of source space densities at high redshifts; the possible dichotomies between evolutionary properties of low- versus high-luminosity and of flat- versus steep-spectrum AGN-powered radio sources; and the nature of sources accounting for the upturn of source counts at sub-mJy levels. It is shown that straightforward extrapolations of evolutionary models, accounting for both the far-IR counts and redshift distributions of star-forming galaxies, match the radio source counts at flux-density levels of tens of µJy remarkably well. We consider the statistical properties of rare but physically very interesting classes of sources, such as GHz Peak Spectrum and ADAF/ADIOS sources, and radio afterglows of gamma -ray bursts. We also discuss the exploitation of large-area radio surveys to investigate large scale structure through studies of clustering and the Integrated Sachs-Wolfe effect. Finally we briefly describe the potential of the new and forthcoming generations of radio telescopes. A compendium of source counts at different frequencies is given in an appendix.