BLAST: A FAR-INFRARED MEASUREMENT OF THE HISTORY OF STAR FORMATION

We directly measure redshift evolution in the mean physical properties (far-infrared luminosity, temperature, and mass) of the galaxies that produce the cosmic infrared background (CIB), using measurements from the Balloon-borne Large Aperture Submillimeter Telescope (BLAST), and Spitzer which constrain the CIB emission peak. This sample is known to produce a surface brightness in the BLAST bands consistent with the full CIB, and photometric redshifts are identified for all of the objects. We find that most of the 70 mu m background is generated at z less than or similar to 1 and the 500 mu m background generated at z greater than or similar to 1. A significant growth is observed in the mean luminosity from similar to 10(9)-10(12) L-circle dot, and in the mean temperature by 10 K, from redshifts 0 < z < 3. However, there is only weak positive evolution in the comoving dust mass in these galaxies across the same redshift range. We also measure the evolution of the far-infrared luminosity density, and the star formation rate history for these objects, finding good agreement with other infrared studies up to z similar to 1, exceeding the contribution attributed to optically selected galaxies.