Follow up of the CFRS with HST, ISO and VLA: the cosmic star formation rate as derived from the FIR luminosity density

Abstract

Properties of CFRS field galaxies up to z=1 are discussed. Estimations of the cosmic star formation rate (SFR) lead to serious problems if they not account for AGN emissions and for light reemitted at IR wavelengths. Deep ISOCAM and VLA photometries on one CFRS field have been performed. Multi-wavelength analyses from UV to Mid-IR and hence to radio allow us to classify sources from their spectral energy distributions. This provides an estimation of the FIR luminosity density related to star formation. The deduced SFR density is free of extinction effects and not contaminated by AGN emissions. About 55+/-20% of the star formation at z<=1 is related to FIR emission. If a non truncated Salpeter IMF is adopted, the derived stellar mass formed from z=0 to z=1 seems too high when compared to the present day stellar mass. An important fraction (30%) of the star formation at z=0.5-1 seems to be related to the rapidly evolving population of compact/Irr galaxies. Larger systems found at z=1, show a slower evolution of their star formation properties.