The first stars mark the transition from the cosmic dark ages to the modern universe we know today, which is filled with stars, galaxies, and heavy elements essential to life. These stars stand out because of the their pristine primordial initial composition and their pre-galactic formation environment. Their unique composition can dramatically alter their evolution, their structure, the way they die as supernovae, and their resulting nucleosynthesis. The very special circumstances and very special 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 imply that their initial mass function could have been quite different from that of all the later generations. Generally it is assumed that these stars on average were significantly more massive than present-day stars.  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. 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.

报告人简介：Alexander Heger is professor of Monash Center for Astrophysics (as a director during 2015-2018), Monash University, Australia. His research focuses on theoretical studies of evolution and nucleosynthesis of massive stars. He has published over 300 refereed papers and got a total citation of over 16,000, with an H-index of 53.  He was elected as an APS fellow in 2009, ASA fellow in 2012, and AIP fellow in 2018. He serves the chief editor of PASA since 2014.