Investigating the impact of different velocity fields on the spectral appearance of Wolf-Rayet stars

TL;DR

This study examines how different stellar wind velocity laws affect the spectral analysis of Wolf-Rayet stars, demonstrating that appropriate velocity assumptions unify spectral modeling across star types.

Contribution

It introduces a comparative analysis of PoWR models with various velocity laws, highlighting the importance of velocity field choice in spectral fitting.

Findings

Velocity law choice significantly alters spectral features.

Proper velocity laws enable unified modeling of different Wolf-Rayet types.

Spectral analysis accuracy depends on wind velocity assumptions.

Abstract

The emission line spectra of WR stars are often formed completely in the optically thick stellar wind. Hence, any assumption on the wind velocity law in a spectral analysis has a profound impact on the determination of the stellar parameters. By comparing Potsdam Wolf-Rayet (PoWR) model spectra calculated with different $\beta$ laws, we show that the velocity field heavily influences the spectra: by using the appropriate $\beta$ laws, the entire range of late and early types can be covered with the same stellar model.