Speaker: Professor Yong-Zhong Qian Institute: University of Minnesota

Time: 14:00 PM, July 23（Thursday）

Location: Large conf. room, 3rd floor

Abstract：

Measurements by the cosmic microwave background experiments such as the Wilkinson Microwave Anisotropy Probe have put the standard cold dark matter cosmology on a firm foundation. This has made it possible to simulate the formation of the first stars in the universe from an ab initio approach. However, this exciting development so far has not proceeded to the point that the mass distribution of the first stars (i.e., their initial mass function, IMF) can be calculated. Estimates of the final masses of these stars based on various simulations range from 10 to 1000 solar masses. It will be shown that observations of elemental abundances in old stars of the Galactic halo can provide important insights into the IMF of the first stars. It will be argued that the first stars are dominantly of 8 to 50 solar masses with an IMF similar to that associated with present star formation in the same mass range.