Moving inhomogeneous envelopes of stars

TL;DR

This paper advances the understanding of massive star winds by developing 3-D models of inhomogeneous stellar atmospheres, leading to more accurate mass-loss rate diagnostics and insights into stellar feedback.

Contribution

It introduces sophisticated 3-D radiation transfer models for inhomogeneous stellar winds, improving spectral analysis and mass-loss rate estimation.

Findings

3-D models reveal wind inhomogeneities significantly affect spectral diagnostics.

New techniques provide consistent stellar wind parameters across multiple wavelengths.

Enhanced understanding of stellar feedback mechanisms in galaxy evolution.

Abstract

Massive stars are extremely luminous and drive strong winds, blowing a large part of their matter into the galactic environment before they finally explode as a supernova. Quantitative knowledge of massive star feedback is required to understand our Universe as we see it. Traditionally, massive stars have been studied under the assumption that their winds are homogeneous and stationary, largely relying on the Sobolev approximation. However, observations with the newest instruments, together with progress in model calculations, ultimately dictate a cardinal change of this paradigm: stellar winds are highly inhomogeneous. Hence, we are now advancing to a new stage in our understanding of stellar winds. Using the foundations laid by V.V. Sobolev and his school, we now update and further develop the stellar spectral analysis techniques. New sophisticated 3-D models of radiation transfer in inhomogeneous expanding media elucidate the physics of stellar winds and improve classical empiric mass-loss rate diagnostics. Applications of these new techniques to multiwavelength observations of massive stars yield consistent and robust stellar wind parameters.