2020/10/16 by Mihir Kulkarni, Eli Visbal, Greg L. Bryan · 2 citations
Physics and Astronomy · #Astronomy and Astrophysical Research #Dark matter #Dark matter halo #Galaxies: Formation, Evolution, Phenomena #Galaxy #Halo #Population #Redshift #Star formation #Stars #Stellar, planetary, and galactic studies #Virial theorem #astro-ph.CO #astro-ph.GA
paper · pdf · doi:10.3847/1538-4357/ac08a3
Submitted to ApJ. 15 pages, 9 figures; corrected typos
openalex created_date 2020/10/15 · arxiv created 2020/10/16 · openalex publication_date 2021/08/01 · arxiv updated 2021/08/25 · openalex updated_date 2026/08/06
Abstract A critical dark matter halo mass ( M crit ) for Population III stars can be defined as the typical minimum halo mass that hosts sufficient cold-dense gas required for the formation of the first stars. The presence of Lyman–Werner (UV) radiation, which can dissociate molecular hydrogen, and the baryon-dark matter streaming velocity both delay the formation of Population III stars by increasing M crit . In this work, we constrain M crit as a function of Lyman–Werner flux (including self-shielding), baryon-dark matter streaming, and redshift using cosmological simulations with a large sample of halos utilizing the adaptive mesh refinement code enzo . We provide a fit for M crit as a function of these quantities, which we expect to be particularly useful for semi-analytical models of early galaxy formation. In addition, we find (i) the measured redshift dependence of M crit in the absence of radiation or streaming is (1 + z ) −1.58 , consistent with a constant virial temperature; (ii) increasing the UV background increases M crit while steepening the redshift dependence, up to (1 + z ) −5.7 ; (iii) baryon-dark matter streaming boosts M crit but flattens the dependence on redshift; (iv) the combination of the two effects is not simply multiplicative.