Beasor, ER, Davies, B, Smith, N, van Loon, JT ORCID: https://orcid.org/0000-0002-1272-3017, Gehrz, RD and Figer, DF (2020) A new mass-loss rate prescription for red supergiants. Monthly Notices of the Royal Astronomical Society, 492 (4). 5994 - 6006.

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Abstract

Evolutionary models have shown the substantial effect that strong mass-loss rates ($\dotM$s) can have on the fate of massive stars. Red supergiant (RSG) mass-loss is poorly understood theoretically, and so stellar models rely on purely empirical $\dotM$–luminosity relations to calculate evolution. Empirical prescriptions usually scale with luminosity and effective temperature, but $\dotM$ should also depend on the current mass and hence the surface gravity of the star, yielding more than one possible $\dotM$ for the same position on the Hertzsprung–Russell diagram. One can solve this degeneracy by measuring $\dotM$ for RSGs that reside in clusters, where age and initial mass (Minit) are known. In this paper we derive $\dotM$ values and luminosities for RSGs in two clusters, NGC 2004 and RSGC1. Using newly derived Minit measurements, we combine the results with those of clusters with a range of ages and derive an Minit-dependent $\dotM$ prescription. When comparing this new prescription to the treatment of mass-loss currently implemented in evolutionary models, we find models drastically overpredict the total mass-loss, by up to a factor of 20. Importantly, the most massive RSGs experience the largest downward revision in their mass-loss rates, drastically changing the impact of wind mass-loss on their evolution. Our results suggest that for most initial masses of RSG progenitors, quiescent mass-loss during the RSG phase is not effective at removing a significant fraction of the H-envelope prior to core-collapse, and we discuss the implications of this for stellar evolution and observations of SNe and SN progenitors.

Item Type: Article
Additional Information: This article has been accepted for publication in the Monthly Notices of the Royal Astronomical Society © 2020, published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.
Uncontrolled Keywords: stars: evolution; stars: massive; stars: mass-loss; supergiants; galaxies: clusters: individual
Subjects: Q Science > QB Astronomy > QB460 Astrophysics
Q Science > QB Astronomy > QB799 Stars
Divisions: Faculty of Natural Sciences > School of Chemical and Physical Sciences
Depositing User: Symplectic
Date Deposited: 30 Mar 2020 14:44
Last Modified: 24 Apr 2020 11:11
URI: https://eprints.keele.ac.uk/id/eprint/7855

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