A Conceptual Analysis of Mass Loss and Frequency Redistribution in Wolf-Rayet Winds

TL;DR

This paper investigates how metallicity influences mass loss in Wolf-Rayet stars using analytic models, revealing a power-law relation that flattens at higher metallicities, which is crucial for understanding their role as gamma-ray burst progenitors.

Contribution

It introduces a simple analytic model to describe the mass loss-metallicity relation in Wolf-Rayet stars, highlighting the power-law behavior and its flattening at higher metallicities.

Findings

Mass loss rate follows a power law with metallicity index 0.88

Relation flattens around log Z/Z_sun ~ -0.5

Model aids understanding of Wolf-Rayet stars as gamma-ray burst progenitors

Abstract

To better understand Wolf-Rayet stars as progenitors of gamma-ray bursts, an understanding of the effect metallicity has on Wolf-Rayet mass loss is needed. Using simple analytic models, we study the Mdot - Z relation of a WN star and compare the results to similar models. We find that Mdot roughly follows a power law in Z with index 0.88 from -2.5 < log Z/Z_sun < -1 and appears to flatten by log Z/Z_sun ~ -0.5.