Linear line spectropolarimetry as a new window to measure 2D and 3D wind geometries

TL;DR

This paper introduces linear spectropolarimetry as a novel technique to measure the two- and three-dimensional geometries of stellar winds, providing insights into how mass loss varies with stellar rotation and latitude.

Contribution

It demonstrates the application of linear spectropolarimetry to different types of massive stars, offering a new observational method to study wind geometries and mass loss.

Findings

Spectropolarimetry distinguishes between pole and equator mass loss.

Applied to various O and Wolf-Rayet stars, including gamma-ray burst progenitors.

Provides new constraints on stellar wind models.

Abstract

Various theories have been proposed to predict how mass loss depends on the stellar rotation rate, both in terms of its strength, as well as its latitudinal dependence, crucial for our understanding of angular momentum evolution. Here we discuss the tool of linear spectropolarimetry that can probe the difference between mass loss from the pole versus the equator. Our results involve several groups of O stars and Wolf-Rayet stars, involving Oe stars, Of?p stars, Onfp stars, as well as the best candidate gamma-ray burst progenitors identified to date.