%0 Generic %1 faisst2015restuv %A Faisst, A. L. %A Capak, P. L. %A Davidzon, I. %A Salvato, M. %A Laigle, C. %A Ilbert, O. %A Onodera, M. %A Hasinger, G. %A Kakazu, Y. %A Masters, D. %A Mobasher, B. %A Sanders, D. %A Silverman, J. D. %A Yan, L. %A Scoville, N. Z. %D 2015 %K absorption dust lines metallicity redshift %T Rest-UV Absorption Lines as Metallicity Estimator: the Metal Content of Star-Forming Galaxies at z~5 %U http://arxiv.org/abs/1512.00018 %X We measure a relation between the depth of four prominent rest-UV absorption complexes and metallicity for local galaxies and verify it up to z~3. We then apply this relation to a sample of 224 galaxies at 3.5 < z < 6.0 (<z> = 4.8) in COSMOS, for which unique UV spectra from DEIMOS and accurate stellar masses from SPLASH are available. The average galaxy population at z~5 and log(M/Msun) > 9 is characterized by 0.3-0.4 dex (in units of 12+log(O/H)) lower metallicities than at z~2, but comparable to z~3.5. We find galaxies with weak/no Ly-alpha emission to have metallicities comparable to z~2 galaxies and therefore may represent an evolved sub-population of z~5 galaxies. We find a correlation between metallicity and dust in good agreement with local galaxies and an inverse trend between metallicity and star-formation rate (SFR) consistent with observations at z~2. The relation between stellar mass and metallicity (MZ relation) is similar to z~3.5, however, there are indications of it being slightly shallower, in particular for the young, Ly-alpha emitting galaxies. We show that, within a "bathtub" approach, a shallower MZ relation is expected in the case of a fast (exponential) build-up of stellar mass with an e-folding time of 100-200 Myr. Due to this fast evolution, the process of dust production and metal enrichment as a function of mass could be more stochastic in the first billion years of galaxy formation compared to later times.

@misc{faisst2015restuv, abstract = {We measure a relation between the depth of four prominent rest-UV absorption complexes and metallicity for local galaxies and verify it up to z~3. We then apply this relation to a sample of 224 galaxies at 3.5 < z < 6.0 (<z> = 4.8) in COSMOS, for which unique UV spectra from DEIMOS and accurate stellar masses from SPLASH are available. The average galaxy population at z~5 and log(M/Msun) > 9 is characterized by 0.3-0.4 dex (in units of 12+log(O/H)) lower metallicities than at z~2, but comparable to z~3.5. We find galaxies with weak/no Ly-alpha emission to have metallicities comparable to z~2 galaxies and therefore may represent an evolved sub-population of z~5 galaxies. We find a correlation between metallicity and dust in good agreement with local galaxies and an inverse trend between metallicity and star-formation rate (SFR) consistent with observations at z~2. The relation between stellar mass and metallicity (MZ relation) is similar to z~3.5, however, there are indications of it being slightly shallower, in particular for the young, Ly-alpha emitting galaxies. We show that, within a "bathtub" approach, a shallower MZ relation is expected in the case of a fast (exponential) build-up of stellar mass with an e-folding time of 100-200 Myr. Due to this fast evolution, the process of dust production and metal enrichment as a function of mass could be more stochastic in the first billion years of galaxy formation compared to later times.}, added-at = {2015-12-02T10:51:17.000+0100}, author = {Faisst, A. L. and Capak, P. L. and Davidzon, I. and Salvato, M. and Laigle, C. and Ilbert, O. and Onodera, M. and Hasinger, G. and Kakazu, Y. and Masters, D. and Mobasher, B. and Sanders, D. and Silverman, J. D. and Yan, L. and Scoville, N. Z.}, biburl = {https://www.bibsonomy.org/bibtex/2e7de1135787086078a4e85bf5e82a26d/miki}, description = {[1512.00018] Rest-UV Absorption Lines as Metallicity Estimator: the Metal Content of Star-Forming Galaxies at z~5}, interhash = {241828b304b29244ed2a750a6536b5a4}, intrahash = {e7de1135787086078a4e85bf5e82a26d}, keywords = {absorption dust lines metallicity redshift}, note = {cite arxiv:1512.00018Comment: 20 pages, 13 figures, 4 tables; Submitted to ApJ}, timestamp = {2015-12-02T10:51:17.000+0100}, title = {Rest-UV Absorption Lines as Metallicity Estimator: the Metal Content of Star-Forming Galaxies at z~5}, url = {http://arxiv.org/abs/1512.00018}, year = 2015 }