Christopher McKee
Salle des séminaires Évry Schatzman, Institut d'Astrophysique de Paris
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| « Massive star formation » |
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Christopher McKee |
| Massive stars generate most of the heavy elements in the universe and have a dominant influence on the evolution of galaxies. Such stars form in dense regions of molecular clouds that have surface densities of order 1 g/cm2; this is similar to the surface density both of contemporary star clusters that contain massive stars and of globular clusters, which had massive stars in the distant past. The turbulent core model for massive star formation predicts that massive stars form in regions of molecular gas that are highly turbulent on a time scale of about 105 yr. The corresponding accretion rate is high enough to overcome the radiation pressure due to the luminosity of the star. Ongoing numerical simulations are consistent with this theoretical picture and show that three-dimensional effects allow massive protostars to continue accreting material at high luminosities. An alternative model for massive star formation, competitive accretion, works only in regions in which the level of turbulence is significantly less than the observed value. |
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vendredi 31 mars 2006 - 11:00 Salle des séminaires Évry Schatzman, Institut d'Astrophysique de Paris |
| Page web du séminaire / Seminar's webpage |