1609.06348
The minimum halo mass for star formation at z=6-8
Finlator, et al
Recent analysis of strongly-lensed sources in the Hubble Frontier Fields indicates that the rest-frame UV LF of galaxies at z=6--8 rises as a power law down to M_UV=-15, and possibly as faint as -12.5. Use predictions from a cosmo radiation hydro sim to map these luminosities onto physical space, constraining the minimum DM halo mass and stellar mass that the FFs probe. While previously-published theoretical studies have suggested or assumed that early SF was suppressed in haloes less massive than 1e9--1e11 Msun, find that recent observations demand vigorous SF in haloes at least as massive as (3.1, 5.6, 10.5)e9 Msun at z=(6,7,8). Likewise, find that FF observations probe down to stellar masses of (8.1, 18, 32)e6 Msun; that is, they are observing the likely progenitors of analogues to Local Group dwarfs such as Pegasus and M32. The sims yield somewhat different constraints than two complementary models that have been invoked in similar analyses, emphasizing the need for further observations constraints on the galaxy-halo connection.
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