The Star Formation and Extinction Evolution of UV-Selected Galaxies over 0<z<1.25
Abstract
We study the co-evolution of extinction and star formation rate in galaxies over 0<z<1.25 in the Chandra Deep Field South (CDFS) field. We use a new stacking technique to obtain mean mid IR and far IR to Far UV flux ratios over the rest near-UV/near-IR color-magnitude diagram. We employ COMBO-17 redshifts and COMBO-17 optical, GALEX far and near UV, Spitzer IRAC and MIPS Mid IR photometry. This technique permits us to probe infrared excess (IRX) ratios and their evolution over almost two orders of magnitude. We use the derived IRX to correct extinction in all bands, and then use rest-frame extinction-corrected H-band and NUV-H colors to derive the specific star formation rate and the stellar mass. We confirm some well known trends and discover a number of interesting new ones. At a given redshift the specific star formation rate is a flat distribution up to a critical mass. For higher masses the specific star formation rate falls steeply. The critical mass increases with redshift. The specific star formation rate increases with redshift. At any given epoch, IRX is a strongly increasing function of mass up to the critical mass. Above this mass the IRX falls. The rise in the total star formation density in higher extinction galaxies is directly tied to the increasing characteristic mass of star forming galaxies. Finally, the IRX at a given mass may increase with decreasing redshift. We interpret these trends using a simple evolutionary model that relates extinction, mass, metallicity, and star formation rate.
- Publication:
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American Astronomical Society Meeting Abstracts
- Pub Date:
- December 2006
- Bibcode:
- 2006AAS...20918304M