The NEWFIRM HETDEX Survey Probing the Growth of Galaxies with Cosmic Time

We propose NEWFIRM K-band imaging over a 28 deg^ 2 equatorial region within SDSS Stripe 82 to finish building a unique and important extragalactic legacy field. This field will soon have 300,000 Lyα-based redshifts at 2< z< 3.5 from the Hobby Eberly Telescope Dark Energy Experiment (HETDEX), deep imaging at 3.6 (micron) and 4.5 (micron) from the Spitzer-HETDEX Exploratory Large Area survey, far-IR data from Herschel, and deep optical imaging from the Dark Energy Survey. The addition of NEWFIRM K-band data will allow us to 1) Measure robust extinction-corrected star-formation rates (SFRs) down to 10 Msol yr^-1 at stellar masses of 10^ 10 Msol; 2) Calculate precise photometric redshifts for the non-Lyα emitters in the sample; and 3) Study how the SFR depends on the dark matter halo mass and local environment. This large survey, together with the spectroscopic completeness and accurate halo …