Universality and Non-Universality in Turbulent Detonation Initiation

TYPEAstrophysics Seminar
Speaker:Robert Fisher
Affiliation:University of Massachusetts, Dartmouth
Time:11:00 - 12:00
Location:Lewiner Seminar Room (412)

Type Ia supernovae (SNe Ia) play a critical role as standardizable candles for cosmology, and are believed to be the result of detonating white dwarfs. Their precise outcome is in a sense balanced on an edge, depending on whether or not a detonation is successfully achieved. Yet, despite the critical role which detonation initiation plays in SNe Ia, a complete theory of detonation initiation has been lacking to date. In this talk, I will describe how turbulence plays a dominant role in the energetics and dynamics of detonation ignition in all major models of SNe Ia. I will also show the first numerical simulations which demonstrate a self-consistent turbulently-driven ignition mechanism. We will further demonstrate that turbulent temperature fluctuations lead to both a universal and non-universal scaling law for the turbulent burning rate in the distributed burning regime. These new insights into detonation initiation help shed light on the origin of SNe Ia.