A Spectroscopic Survey of Redshift 1.4 ≾ z ≾ 3.0 Galaxies in the GOODS-North Field: Survey Description, Catalogs, and Properties

Abstract

We present the results of a spectroscopic survey with LRIS-B on Keck of more than 280 star-forming galaxies and AGNs at redshifts 1.4 ≾ z ≾ 3.0 in the GOODS-N field. Candidates are selected by their U_nGR colors using the "BM/BX" criteria to target redshift 1.4 ≾ z ≾ 2.5 galaxies and the LBG criteria to target redshift z ~ 3 galaxies; combined these samples account for ~25%-30% of the R and K_s band counts to R = 25.5 and K_s(AB) = 24.4, respectively. The 212 BM/BX galaxies and 74 LBGs constitute the largest spectroscopic sample of galaxies at z > 1.4 in GOODS-N. Extensive multiwavelength data allow us to investigate the stellar populations, stellar masses, bolometric luminosities (L_(bol)), and extinction of z ~ 2 galaxies. Deep Chandra and Spitzer data indicate that the sample includes galaxies with a wide range in L_(bol) (≃10^(10) to >10^(12) L_☉) and 4 orders of magnitude in dust obscuration (L_(bol)/L_(UV)). The sample includes galaxies with a large dynamic range in evolutionary state, from very young galaxies (ages ≃50 Myr) with small stellar masses (M* ≃ 10^9 M_☉) to evolved galaxies with stellar masses comparable to the most massive galaxies at these redshifts (M* > 10^(11) M_☉). Spitzer data indicate that the optical sample includes some fraction of the obscured AGN population at high redshifts: at least 3 of 11 AGNs in the z > 1.4 sample are undetected in the deep X-ray data but exhibit power-law SEDs longward of ~2 μm (rest frame) indicative of obscured AGNs. The results of our survey indicate that rest-frame UV selection and spectroscopy presently constitute the most timewise efficient method of culling large samples of high-redshift galaxies with a wide range in intrinsic properties, and the data presented here will add significantly to the multiwavelength legacy of GOODS.

Files

Additional details