Oct 23, 2014

Marina Orio, University of Wisconsin-Madison

"Single White Dwarfs as Progenitors of Type Ia Supernovae?"

The "normally" accepted paradigm for type Ia supernovae (SNe Ia) involves a massive CO white dwarf, or two white dwarfs, in a binary system. However, more and more evidence is being gathered, showing two observational facts: a) A very large fraction of SNe Ia must explode on sub-Chandrasekhar mass white dwarfs, b) The SN Ia rate depends on the star formation rate. I will show how these observations can be explained with a simple model, in which a single white dwarfs triggers explosive pycnonuclear reactions involving impurities of hydrogen or helium. An explosion may occur even in the initial post-AGB cooling phase for very massive (m>1.2 M(sol) white dwarfs, or much later, just at the onset of the Debye cooling for white dwarfs in the 0.8-1.35 M(sol). Is this the the new road to take to fully understand the SNe Ia? And are these powerful explosions really useful standard candles for cosmology?


Event Details

Oct 23, 2014


4421 Sterling Hall

Coffee served at 3:30pm; talk starts at 3:45pm

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