Colloquium on Nov. 29th, 2018: Direct collision of white dwarfs as a major channel for type Ia supernovae explosions

Speaker: 东苏勃（北京大学）/ Subo Dong (Peking University)

Venue: Gewu 4410

Time: 3:00 PM, Thursday, 29th November, 2018

Abstract: The field of type Ia supernova (SN Ia) explosion physics is in a crisis. Decades of theoretical researches fail to demonstrate that successful explosions can be convincingly achieved from the popular single degenerate and double degenerate merger models. A growing number of observational evidences contradict these two popular scenarios to explain the SN Ia population. We argue that the direct white dwarf-white dwarf collisions in the field multiple stellar systems is a promising mechanism to explain the SN Ia population. Not only do collisions explain several robust features across the entire SN Iapopulation, but also their predictions of the bi-modal Ni56 distributions in the ejecta are recently discovered observationally, providing direct evidence of WD-WD collisions for some SNe Ia. I will discuss key observational tests on the SNe Ia models enabled by the All Sky Automatic Survey for SuperNovae (ASAS-SN)-- the most successful bright supernova survey at present.

Personal Information:

2004年本科毕业于南京大学天文系；2009年获美国俄亥俄州立大学天文学博士学位；后得到NASA Carl Sagan Fellowship资助，2009-2013年在美国普林斯顿高等研究所从事博士后研究；2013年起为北京大学科维理天文与天体物理研究所研究员，于2014年入选青年千人项目。主要研究兴趣是时域天文，研究工作包括系外行星，超新星，微引力透镜和动力学等方向。