Distinguishing Quiescent and Dusty Star-forming Galaxies

Large photometric surveys provide a rich source of observations of quiescent galaxies, including a surprisingly large population at z > 1. However, identifying large, but clean, samples of quiescent galaxies has proven difficult because of their near-degeneracy with interlopers such as dusty, star-forming galaxies. We describe a new technique for selecting quiescent galaxies based upon t-distributed stochastic neighbor embedding which provides an improvement both over UVJ. It also may be able to select quiescent galaxies more efficiently at higher redshifts than the training sample.