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  • A Spectroscopic Survey of R...
    Reddy, Naveen A; Steidel, Charles C; Erb, Dawn K; Shapley, Alice E; Pettini, Max

    The Astrophysical journal, 12/2006, Letnik: 653, Številka: 2
    Journal Article

    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 sub(n)GR colors using the "BM/BX" criteria to target redshift 1.4 z 2.5 galaxies and the LBG criteria to target redshift z 6 3 galaxies; combined these samples account for 625%-30% of the R and K sub(s) band counts to R = 25.5 and K sub(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 sub(bol)), and extinction of z 6 2 galaxies. Deep Chandra and Spitzer data indicate that the sample includes galaxies with a wide range in L sub(bol) ( 10 super(10) to >10 super(12) L sub( )) and 4 orders of magnitude in dust obscuration (L sub(bol)/L sub(UV)). The sample includes galaxies with a large dynamic range in evolutionary state, from very young galaxies (ages 650 Myr) with small stellar masses (M* 10 super(9) M sub( )) to evolved galaxies with stellar masses comparable to the most massive galaxies at these redshifts (M* > 10 super(11) M sub( )). 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 62 km (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.