Copy the page URI to the clipboard
Gruppioni, Carlotta; Oliver, Seb and Serjeant, Stephen
(2001).
DOI: https://doi.org/10.1023/A:1017544300657
URL: http://www.springerlink.com/content/k61562rr106422...
Abstract
We present new results on the nature of the faint radio galaxy population obtained from a deep identification study in the Marano Field. This work represents the highest identification fractions attained to date in literature for sub-mJy radio samples. Star-forming galaxies constitute a significant fraction of the optical counterparts of sub-mJy radio sources, although they are not the dominant identification class (as formerly believed). We also present a new determination of the co-moving star formation density from z=0 to z~=0.35 using the radio luminosity function of star-forming galaxies. For the local determination, we used a sample of 231 spiral galaxies taken from the B<=12 Revised Shapley-Ames Catalogue, while for the non-local determination, we used a sample of 87 star-forming galaxies taken from the Benn et al. (1993) sample. The inferred local star formation rate is about twice as great as the H_alpha estimate, while the intermediate 0.05<z <0.35 star formation rate is consistent with coeval ultraviolet and H_alpha estimates. This is due to large-scale structure, rarely accounted for in estimates of the cosmic star formation history; the situation could improve significantly with deep moderate-area radio surveys.