English

The Cosmic Microwave Background and the Stellar Initial Mass Function

Astrophysics of Galaxies 2018-09-25 v2

Abstract

We argue that an increased temperature in star-forming clouds alters the stellar initial mass function to be more bottom-light than in the Milky Way. At redshifts z6z \gtrsim 6, heating from the cosmic microwave background radiation produces this effect in all galaxies, and it is also present at lower redshifts in galaxies with very high star formation rates (SFRs). A failure to account for it means that at present, photometric template fitting likely overestimates stellar masses and star formation rates for the highest-redshift and highest-SFR galaxies. In addition this may resolve several outstanding problems in the chemical evolution of galactic halos.

Keywords

Cite

@article{arxiv.1809.03502,
  title  = {The Cosmic Microwave Background and the Stellar Initial Mass Function},
  author = {Adam S. Jermyn and Charles L. Steinhardt and Christopher A. Tout},
  journal= {arXiv preprint arXiv:1809.03502},
  year   = {2018}
}

Comments

9 pages, 5 figures. Published in MNRAS. Added further references

R2 v1 2026-06-23T04:01:15.989Z