| Autor: |
Yusof, N., Hirschi, R., Eggenberger, P., Ekström, S., Georgy, C., Sibony, Y., Crowther, P.A., Meynet, G., Kassim, H.A., Harun, W.A.W., Maeder, A., Groh, J.H., Farrell, E., Murphy, L. |
| Jazyk: |
angličtina |
| Rok vydání: |
2022 |
| ISSN: |
0035-8711 |
| Popis: |
We present a grid of stellar models at supersolar metallicity (Z = 0.020) extending the previous grids of Geneva models at solar and sub-solar metallicities. A metallicity of Z = 0.020 was chosen to match that of the inner Galactic disc. A modest increase of 43 per cent (= 0.02/0.014) in metallicity compared to solar models means that the models evolve similarly to solar models but with slightly larger mass-loss. Mass-loss limits the final total masses of the supersolar models to 35 M⊙ even for stars with initial masses much larger than 100 M⊙. Mass-loss is strong enough in stars above 20 M⊙ for rotating stars (25 M⊙ for non-rotating stars) to remove the entire hydrogen-rich envelope. Our models thus predict SNII below 20 M⊙ for rotating stars (25 M⊙ for non-rotating stars) and SNIb (possibly SNIc) above that. We computed both isochrones and synthetic clusters to compare our supersolar models to the Westerlund 1 (Wd1) massive young cluster. A synthetic cluster combining rotating and non-rotating models with an age spread between log10(age/yr) = 6.7 and 7.0 is able to reproduce qualitatively the observed populations of WR, RSG, and YSG stars in Wd1, in particular their simultaneous presence at log10(L/L⊙) = 5–5.5. The quantitative agreement is imperfect and we discuss the likely causes: synthetic cluster parameters, binary interactions, mass-loss and their related uncertainties. In particular, mass-loss in the cool part of the HRD plays a key role. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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