New Determinations of the UV Luminosity Functions from z~9 to z~2 show a remarkable consistency with halo growth and a constant star formation efficiency

R. J. Bouwens; P. A. Oesch; M. Stefanon; G. Illingworth; I. Labbe; N. Reddy; H. Atek; M. Montes; R. Naidu; T. Nanayakkara; E. Nelson; S. Wilkins

doi:10.3847/1538-3881/abf83e

arXiv · 2102.07775

New Determinations of the UV Luminosity Functions from z~9 to z~2 show a remarkable consistency with halo growth and a constant star formation efficiency

R. J. Bouwens·P. A. Oesch·M. Stefanon·G. Illingworth·I. Labbe·N. Reddy·H. Atek·M. Montes·R. Naidu·T. Nanayakkara·E. Nelson·S. Wilkins

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Abstract

Here we provide the most comprehensive determinations of the rest-frame $UV$ LF available to date with HST at z~2, 3, 4, 5, 6, 7, 8, and 9. Essentially all of the non-cluster extragalactic legacy fields are utilized, including the Hubble Ultra Deep Field (HUDF), the Hubble Frontier Field parallel fields, and all five CANDELS fields, for a total survey area of 1136 arcmin^2. Our determinations include galaxies at z~2-3 leveraging the deep HDUV, UVUDF, and ERS WFC3/UVIS observations available over a ~150 arcmin^2 area in the GOODS North and GOODS South regions. All together, our collective samples include >24,000 sources, >2.3x larger than previous selections with HST. 5766, 6332, 7240, 3449, 1066, 601, 246, and 33 sources are identified at z~2, 3, 4, 5, 6, 7, 8, and 9, respectively. Combining our results with an earlier z~10 LF determination by Oesch+2018a, we quantify the evolution of the $UV$ LF. Our results indicate that there is (1) a smooth flattening of the faint-end slope alpha from alpha~-2.4 at z~10 to -1.5 at z~2, (2) minimal evolution in the characteristic luminosity M* at z>~2.5, and (3) a monotonic increase in the normalization log_10 phi* from z~10 to z~2, which can be well described by a simple second-order polynomial, consistent with an "accelerated" evolution scenario. We find that each of these trends (from z~10 to z~2.5 at least) can be readily explained on the basis of the evolution of the halo mass function and a simple constant star formation efficiency model.

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R. J. Bouwens, P. A. Oesch, M. Stefanon, G. Illingworth, I. Labbe, N. Reddy, H. Atek, M. Montes, R. Naidu, T. Nanayakkara, E. Nelson, S. Wilkins. 2021-02-15. New Determinations of the UV Luminosity Functions from z~9 to z~2 show a remarkable consistency with halo growth and a constant star formation efficiency. https://doi.org/10.3847/1538-3881/abf83e

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