Hostname: page-component-78c5997874-g7gxr Total loading time: 0 Render date: 2024-11-10T13:57:10.813Z Has data issue: false hasContentIssue false
  • English
  • Français

Massive Stars as Cosmic Engines Through the Ages

Published online by Cambridge University Press:  01 December 2007

André Maeder ,
Georges Meynet ,
Sylvia Ekström ,
Raphael Hirschi  and
Cyril Georgy
André Maeder
Affiliation:
Geneva Observatory, University of Geneva, CH–1290 Sauverny, Switzerland email: andre.maeder@obs.unige.ch, georges.meynet@obs.unige.ch, sylvia.ekstrom@obs.unige.ch, cyril.georgy@obs.unige.ch
Georges Meynet
Affiliation:
Geneva Observatory, University of Geneva, CH–1290 Sauverny, Switzerland email: andre.maeder@obs.unige.ch, georges.meynet@obs.unige.ch, sylvia.ekstrom@obs.unige.ch, cyril.georgy@obs.unige.ch
Sylvia Ekström
Affiliation:
Geneva Observatory, University of Geneva, CH–1290 Sauverny, Switzerland email: andre.maeder@obs.unige.ch, georges.meynet@obs.unige.ch, sylvia.ekstrom@obs.unige.ch, cyril.georgy@obs.unige.ch
Raphael Hirschi
Affiliation:
Astrophysics, EPSAM, University of Keele email: r.hirschi@epsam.keele.ac.uk
Cyril Georgy
Affiliation:
Geneva Observatory, University of Geneva, CH–1290 Sauverny, Switzerland email: andre.maeder@obs.unige.ch, georges.meynet@obs.unige.ch, sylvia.ekstrom@obs.unige.ch, cyril.georgy@obs.unige.ch
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

Some useful developments in the model physics are briefly presented, followed by model results on chemical enrichments and WR stars. We discuss the expected rotation velocities of WR stars. We emphasize that the (C+O)/He ratio is a better chemical indicator of evolution for WC stars than the C/He ratios. With or without rotation, at a given luminosity the (C+O)/He ratios should be higher in regions of lower metallicity Z. Also, for a given (C+O)/He ratio the WC stars in lower Z regions have higher luminosities. The WO stars, which are likely the progenitors of supernovae SNIc and of some GRBs, should preferentially be found in regions of low Z and be the descendants of very high initial masses. Finally, we emphasize the physical reasons why massive rotating low Z stars may also experience heavy mass loss.

Keywords

stars: early-type – stars: Wolf-Rayet – stars: rotation – stars: mass loss
Type
Contributed Papers
Information
Proceedings of the International Astronomical Union , Volume 3 , Symposium S250: Massive Stars as Cosmic Engines , December 2007 , pp. 3 - 16
Copyright
Copyright © International Astronomical Union 2008

References

Asplund, M., Grevesse, N., Sauval, A. J., et al. 2004, A&A, 417, 751Google Scholar
Chiappini, C., Hirschi, R., Meynet, G., et al. 2006, A&A, 449, 27Google Scholar
Conti, P. S. 1976, Bull. Soc. Roy. Sci. Liege, 9, 193Google Scholar
Conti, P. S., Greenstein, J. L., Spinrad, , et al. 1967, ApJ, 148, 105CrossRefGoogle Scholar
Crowther, P. 2007 ARA&A, 45, 177Google Scholar
Ekström, S. 2008, Thesis, University of Geneva, in prep.Google Scholar
Heap, S. R., Lanz, T., & Hubeny, I. 2006, ApJ, 638, 409CrossRefGoogle Scholar
Herrero, A. 2003, in: Charbonnel, C., Schaerer, D., & Meynet, G. (eds.), CNO in the Universe, (San Francisco: ASP), ASP Conf. Ser., 304, 10Google Scholar
Huang, W. & Gies, D. R. 2006a, ApJ, 648, 580CrossRefGoogle Scholar
Huang, W. & Gies, D. R. 2006b, ApJ, 648, 591CrossRefGoogle Scholar
Hunter, I., Dufton, P. L., Smartt, S. J., et al. 2007, A&A, 466, 277Google Scholar
Ignace, R., Cassinelli, J. P., Tracy, G., et al. 2007, ApJ, 669, 600CrossRefGoogle Scholar
Lamers, H. J. G. L. M. & Morton, D. C. 1976, ApJS, 32, 715CrossRefGoogle Scholar
Langer, N. 1991, A&A, 248, 531Google Scholar
Maeder, A. 1999 A&A, 347, 185Google Scholar
Maeder, A. & Zahn, J. P. 1998, A&A, 334, 1000Google Scholar
Maeder, A. & Meynet, G. 2005, A&A, 440, 1041Google Scholar
Maeder, A., Georgy, C., & Meynet, G. 2008, A&A, 479, L37Google Scholar
Meynet, G. & Maeder, A. 2000, A&A, 361, 101Google Scholar
Meynet, G. & Maeder, A. 2002, A&A, 390, 561Google Scholar
Meynet, G. & Maeder, A. 2003, A&A, 404, 975Google Scholar
Meynet, G. & Maeder, A. 2005, A&A, 429, 581Google Scholar
Meynet, G., Ekström, S., & Maeder, A. 2006, A&A, 447, 623Google Scholar
Morton, D. C., 1976, Bull. American Astr. Soc. 8, 138Google Scholar
Smith, L. F. 1968, MNRAS, 141, 317CrossRefGoogle Scholar
Smith, L. F. & Hummer, D. G. 1988, MNRAS, 230, 511CrossRefGoogle Scholar
Smith, L. F. & Maeder, A. 1991, A&A 241, 77Google Scholar
Spruit, H. C. 2002, A&A, 381, 923Google Scholar
Trundle, C., Dufton, P. L., Hunter, I. et al. 2007, A&A, 471, 625Google Scholar
Zahn, J. P. 1992, A&A, 265, 115Google Scholar