The statistical properties of stars at redshift, z=5, compared with the present epoch
Abstract
We report the statistical properties of stars and brown dwarfs obtained from three radiation hydrodynamical simulations of star cluster formation with metallicities of 1, 1/10 and 1/100 of the solar value. The star-forming clouds are subjected to cosmic microwave background radiation that is appropriate for star formation at a redshift z=5. The results from the three calculations are compared to each other, and to similar previously published calculations that had levels of background radiation appropriate for present-day (z=0) star formation. Each of the calculations treat dust and gas temperatures separately and include a thermochemical model of the diffuse interstellar medium. We find that whereas the stellar mass distribution is insensitive to the metallicity for present-day star formation, at z=5 the characteristic stellar mass increases with increasing metallicity and the mass distribution has a deficit of brown dwarfs and low-mass stars at solar metallicity compared to the Galactic initial mass function. We also find that the multiplicity of M-dwarfs decreases with increasing metallicity at z=5. These effects are a result of metal-rich gas being unable to cool to as low temperatures at z=5 compared to at z=0 due to the hotter cosmic microwave background radiation, which inhibits fragmentation at high densities.
Cite
@article{arxiv.2211.15727,
title = {The statistical properties of stars at redshift, z=5, compared with the present epoch},
author = {Matthew R. Bate},
journal= {arXiv preprint arXiv:2211.15727},
year = {2022}
}
Comments
Accepted for publication in MNRAS. 21 pages, 15 figures. 12 animations available at: http://www.astro.ex.ac.uk/people/mbate/Cluster/clusterRedshift5.html. arXiv admin note: substantial text overlap with arXiv:1901.03713