A Redshift-independent Efficiency Model: Star Formation and Stellar Masses in Dark Matter Halos at z ≳ 4

Citation:

Tacchella S, Bose S, Conroy C, Eisenstein DJ, Johnson BD. A Redshift-independent Efficiency Model: Star Formation and Stellar Masses in Dark Matter Halos at z ≳ 4. The Astrophysical Journal. 2018;868.

Date Published:

December 1, 2018

Abstract:

We explore the connection between the UV luminosity functions (LFs) ofhigh-z galaxies and the distribution of stellar masses and starformation histories (SFHs) in their host dark matter halos. We provide abaseline for a redshift-independent star formation efficiency model towhich observations and models can be compared. Our model assigns a starformation rate (SFR) to each dark matter halo based on the growth rateof the halo and a redshift-independent star formation efficiency. Thedark matter halo accretion rate is obtained from a high-resolutionN-body simulation in order to capture the stochasticity in accretionhistories and to obtain spatial information for the distribution ofgalaxies. The halo mass dependence of the star formation efficiency iscalibrated at z = 4 by requiring a match to the observed UV LF at thisredshift. The model then correctly predicts the observed UV LF at z =5–10. We present predictions for the UV luminosity and stellarmass functions, JWST number counts, and SFHs. In particular, we find astellar-to-halo mass relation at z = 4–10 that scales with halomass at M h < 1011 M as M ∝ M h2, with anormalization that is higher than the relation inferred at z = 0. Theaverage SFRs increase as a function of time to z = 4, although there is

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