Astronomy Tea Talk

  Using the deepest HST and Spitzer/IRAC images available over fields likethe GOODS fields, we have found large samples of high-redshift galaxies(z>4-8) with a wide range of luminosities. With this remarkable dataset we have also produced fairly robust estimates of some of the properties of these galaxies, in particular, their star formation rates and stellar masses.  In this talk I will primarily discuss the correlation that exists between these two quantities. The "main sequence" of star forming galaxies is not new at high redshift but unlike what is observed at z<2,the relation does not seem to evolve as strongly at earlier times. This posses an interesting puzzle to theory, sometimes referred to as the specific SFR plateau, which has received a fair amount of attention recently. In this presentation I will review the latest progress in the estimate of the specific SFR evolution with redshift and I will discuss what these observations suggest about the way in which galaxies grew in the early Universe.