The Cosmic Star Formation Rate Density since z∼10: Constraints on Galaxies in the First Gyr

The recent extraordinarily deep WFC3/IR data from the HUDF09 program has dramatically expanded our insights to the galaxy population at z∼7–9, and given us hints as to the population at z∼10. In particular, as part of our program of identifying and characterizing the galaxy population at high redshift (z>6), we have been undertaking a thorough analysis of the luminosity functions to much lower luminosities than previous studies. We have used very deep fields (the HUDF, HUDF09 and the HUDF05 datasets), as well as extremely faint objects from highly‐magnified sources from cluster lensing surveys, to derive the contribution from lower luminosity galaxies to as faint as 0.03–0.06 L* from z∼7 to z∼2. Recent results on the contribution of ULIRGS to star‐forming galaxies indicate that in the first 1–2 Gyr the dominant contributors to the star formation rate density in the universe are the lower luminosity and lower mass objects that are fully represented in the Lyman Break population at z∼4–7 and at earlier time...