Upper limit on star formation and metal enrichment in minihaloes

作者：Cen Renyue^*

来源：Monthly Notices of the Royal Astronomical Society, 2017, 465(1): L69-L73.

DOI：10.1093/mnrasl/slw204

• stars: formation
• stars: Population III
• ISM: abundances
• galaxies: formation
• galaxies: ISM

An analysis of negative radiative feedback from resident stars in minihaloes is performed. It is found that the most effective mechanism to suppress star formation is provided by infrared photons from resident stars via photodetachment of H-. It is shown that a stringent upper bound on (total stellar mass, metallicity) of (similar to 1000M(circle dot), -3.3 +/- 0.2) in any newly minted atomic cooling halo can be placed, with the actual values possibly significantly lower. This has both important physical ramifications on formation of stars and supermassive black seeds in atomic cooling haloes at high redshift, pertaining to processes of low-temperature metal cooling, dust formation and fragmentation, and direct consequences on the faint end galaxy luminosity function at high redshift and cosmological reionization. The luminosity function of galaxies at the epoch of reionization may be substantially affected due to the combined effect of a diminished role of minihaloes and an enhanced contribution from Population III stars in atomic cooling haloes. Upcoming results on reionization optical depth from Planck High-Frequency Instrument data may provide a significant constraint on and a unique probe of this star formation physical process in minihaloes. As a numerical example, in the absence of significant contributions from minihaloes with virial masses below 1.5 x 10(8) M-circle dot, the reionization optical depth is expected to be no greater than 0.065, whereas allowing for minihaloes of masses as low as (10(7)M(circle dot), 10(6.5)M(circle dot)) to form stars unconstrained by this self-regulation physical process, the reionization optical depth is expected to exceed (0.075, 0.085), respectively.

• 出版日期2017-2