Abstract

It is well established that nearly 100% of the most massive galaxies in the local Universe have stopped forming stars (quiescent). Simulations and theoretical models show that a combination of physical effects can recover this present-day quiescent fraction. These models also predict that the quiescent fraction of massive galaxies declines with increasing redshift; such that massive quiescent galaxies should be fairly rare at z > 2, and nearly zero at z~3.5. The frontier in studying the evolution of massive galaxies is now at z > 3. Surveys over small fields find varying, but significant quiescent fractions among massive galaxies at z = 3.5, where simulations and models fail to produce substantial, if any, of these sources. Previous surveys of massive quiescent galaxies also suffer from large uncertainties due to small sample sizes. In this talk I will present a conservative sample of 33 high redshift massive quiescent galaxies in the 22 deg2 SHELA survey, as well as the selection criteria we have employed to robustly select these galaxies. I will also present a new redshift luminosity prior and investigate whether such a prior is constructive in reducing low redshift contaminants for these particular sources. This work will be the first step in robustly constraining the quiescent fraction at redshifts z=3-5 using a large sample of massive quiescent galaxies in SHELA.