Stellar evolution with rotation X: Wolf-Rayet star populations at solar metallicity
نویسندگان
چکیده
We examine the properties of Wolf–Rayet (WR) stars predicted by models of rotating stars taking account of the new mass loss rates for O–type stars and WR stars (Vink et al. 2000, 2001; Nugis & Lamers 2000) and of the wind anisotropies induced by rotation. We find that the rotation velocities v of WR stars are modest, i.e. about 50 km s, not very dependant on the initial v and masses. For the most massive stars, the evolution of v is very strongly influenced by the values of the mass loss rates; below ∼12 M⊙ the evolution of rotation during the MS phase and later phases is dominated by the internal coupling. Massive stars with extreme rotation may
منابع مشابه
The effects of rotation on Wolf–Rayet stars and on the production of primary nitrogen by intermediate mass stars
We use the rotating stellar models described in the paper by A. Maeder & G. Meynet in this volume to consider the effects of rotation on the evolution of the most massive stars into and during the Wolf–Rayet phase, and on the post-Main Sequence evolution of intermediate mass stars. The two main results of this discussion are the following. First, we show that rotating models are able to account...
متن کاملImplications of the metallicity dependence of Wolf-Rayet winds
Aims. Recent theoretical predictions for the winds of Wolf-Rayet stars indicate that their mass-loss rates scale with the initial stellar metallicity in the local Universe. We aim to investigate how this predicted dependence affects the models of Wolf-Rayet stars and their progeny in different chemical environments. Methods. We compute models of stellar structure and evolution for Wolf-Rayet st...
متن کاملMassive star evolution at high metallicity
After a review of the many effects of metallicity on the evolution of rotating and non-rotating stars, we discuss the consequences of a high metallicity on massive star populations and on stellar nucleosynthesis. The most striking effect of high metallicity is to enhance the amount of mass lost by stellar winds. Typically at a metallicity Z = 0.001 only 9% of the total mass returned by non-rota...
متن کاملStellar Populations in the Central Galaxies of Fossil Groups
It is inferred from the symmetrical and luminous X-ray emission of fossil groups that they are mature, relaxed galaxy systems. Cosmological simulations and observations focusing on their dark halo and inter-galactic medium properties confirm their early formation. Recent photometric observations suggest that, unlike the majority of non-fossil brightest group galaxies (BGGs), the central early-t...
متن کاملPopulations of massive stars in galaxies, implications for the stellar evolution theory
After a brief review of the observational evidences indicating how the populations of Be stars, red/blue supergiants, Wolf-Rayet stars vary as a function of metallicity, we discuss the implications of these observed trend for our understanding of the massive star evolution. We show how the inclusion of the effects of rotation in stellar models improves significantly the correspondence between t...
متن کامل