Oct 23, 2014

Marina Orio, , University of Wisconsin

"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

Date:
Oct 23, 2014

Time:
3:30–5pm

Location:
4421 Sterling Hall

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

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