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arXiv · 1809.03502

The Cosmic Microwave Background and the Stellar Initial Mass Function

Adam S. Jermyn·Charles L. Steinhardt·Christopher A. Tout
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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 $z \gtrsim 6$, 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.

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Adam S. Jermyn, Charles L. Steinhardt, Christopher A. Tout. 2018-09-10. The Cosmic Microwave Background and the Stellar Initial Mass Function. https://doi.org/10.1093/mnras%2Fsty2123

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