Abstract

Understanding the formation and evolution of massive quiescent galaxies are necessary to understanding how galaxies grow and cease star-formation. Recent observations with sensitive near-infrared imaging cameras have detected a population of massive quiescent galaxies in the early Universe (z~3-5), at an abundance that current cosmological simulations are unable to produce. One key challenge with characterizing these galaxies arise from uncertainties in their photometric redshifts. Degeneracies between SEDs of low redshift (z~1) dusty star forming galaxies (DSFG) and high-z massive quiescent galaxies implies that based purely on photometric fitting, a catalog of high-z massive quiescent galaxies will have a high contamination rate of low-z sources. While a redshift-luminosity prior combined with photometric fitting will greatly reduce contamination by nearby DSFGs, previously used priors do not allow the presence of any moderately bright galaxies at z > 3. In this talk, I will present a new redshift luminosity prior generated from the recent "Santa Cruz" semi-analytic model (Somerville et al. 2015), and how it can be used to constrain redshift probabilities for massive high-z galaxies. We will use this prior to generate a high confidence sample of massive galaxies at z~3-5, from which we can constrain the quiescent sample and pave the way for future spectroscopic observations of these enigmatic sources to understand their formation.