Wolf-Rayet nebulae

11th Pacific Rim Conference on Stellar Astrophysics: Physics and Chemistry of the Late Stages of Stellar Evolution

物理学;天文学

Chu, You-Hua^1

Institute of Astronomy and Astrophysics, Academia Sinica AS/NTU, No.1, Roosevelt Rd, Taipei

10617, Taiwan^1

关键词: Abundance analysis;    Effective temperature;    Elemental abundance;    Evolutionary stage;    Interstellar mediums;    Magellanic Clouds;    Stellar evolutions;    X ray spectral properties;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/728/3/032007/pdf
DOI  :  10.1088/1742-6596/728/3/032007

学科分类：天文学(综合)

来源: IOP

【 摘 要 】

Since the discovery of nebulae around Wolf-Rayet (WR) stars in the 1960s, it has been established that WR stars are massive stars at advanced evolutionary stages and that their surrounding nebulae result from the interactions between the stellar mass loss and the ambient interstellar medium. Surveys of WR nebulae have been made in the Galaxy, Magellanic Clouds, and other nearby galaxies in the Local Group. Some WR nebulae exhibit He II λ4686 line emission, indicating stellar effective temperatures of 90 - 100 x 103K. The shocked fast stellar winds from WR nebulae have been detected in soft X-rays, but theoretical models have not been able to reproduce the observed X-ray spectral properties. Elemental abundances of WR nebulae consisting of synthesized stellar material can constrain stellar evolution models, but high-dispersion spectra are needed to kinematically separate the expanding shell of a WR nebula and the background interstellar medium for accurate abundance analyses.