In the Milky Way there exists a significant population of old and metal-rich stars on highly eccentric orbits, most likely born in-situ. It is not 100% clear how this in-situ halo population came about. Perhaps it can be produced by "splashing" up the prehistoric disk of the Galaxy as a result of an early merger with a massive dwarf satellite. Alternatively, these stars could be born on radial orbits, for example, in an outflow accompanying an ancient star-formation burst.
This work is based on the recent publication:
https://ui.adsabs.harvard.edu/abs/2020MNRAS.494.3880B/abstract
BIO
The speaker did his undergraduate studies at the Moscow State University and his PhD at Oxford. After the PhD he moved to the Institute of Astronomy in Cambridge University first as a Postdoctoral Associate then as a Research Fellow and finally as a member of staff.
Host: Zheng Cai
