Seminar Details

Talk 1 - RCB Stars and the DD Merger Scenario, Talk 2 - Sub Chandrasekhar He Detonation Models for SNIa, and Talk 3 - Determining Dominant Factors in the Chemical Evolution of Dwarf Spheroi

Truran Group ,
Monday, April 8, 12:30 PM - JINA Pizza Lunch
Biomedical & Physical Sciences Bldg., Rm. 1400

Abstract 1 - R Coronae Borealis stars are objects that have been observed to have very peculiar nucleosynthetic signatures. However, the physics leading to the observations is still uncertain. I will discuss the possible astrophysical models and a couple of nuclear reactions that may explain some of the interesting properties of these stars. Abstract 2 - We re-examine the scenario of detonations in helium layers, accreted on carbon-oxygen (CO) cores. Assuming that the outburst occurs on a carbon WD that accretes helium, carbon enrichment can take place if there is dredge up mixing at the bottom of the envelope prior to the ignition of the detonation. Preliminary 1D models show that the helium envelope is indeed unstable to convection about a day before the runaway. We intend to examine this interesting possibility for the mixing process by performing 1D and 2D simulations of the pre runaway evolution. Abstract 3 - Simulations of galactic chemical evolution have the potential to constrain the scales of star formation events and galactic gas accretion/loss events, potentially helping to distinguish between the different mechanisms hypothesized to be involved. I will discuss a statistical approach to determining such constraints using chemical evolution simulations as well as some preliminary results of the method when applied to Sculptor.