CAA Seminar (Dec.20,2016):Life and Death of the First Stars
Source:Seminars Date:2016/12/28

Time: 11:15--12:15,20th December.

Address: CAA lecture Hall,Jianchuan Road 955(我享我家大厦2楼)


Title: Life and Death of the First Stars

Speaker:Prof. Alexander Heger (University of Minnestota)

Abstract:

The first stars mark the transition from the cosmic dark ages to the modern universe we know today, filled with stars, galaxies, and heavyelements essential to life. They are very unique because of the their pristine primordial initial composition and their pre-galacticformation.heir unique composition can dramatically alter their evolution, their structure,the way they die as supernovae,and their resulting nucleosynthesis. The very special environment and time in the evolution of the universe where they were born,out of the dark matter halos preceding the first galaxies,along with their pristine composition, may allow that their initial mass function could have been quite different from that of all the later generations.Some speculations exist that even supermassive primordial stars may have formed that laid the basis for supermassive black holes in the centres of early galaxies,but generally it is assumed that these stars on average were significantly more massive than present-day stars.In this talk I will give an overview of the evolution and death of these first stars and their supernova.I will also discuss nucleosynthesis signatures as possible diagnostics that have survived to the present day.