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Common envelope WD-core merger as Type Ia supernova progenitors

TYPEAstrophysics Seminar
Speaker:Mr. Marjan Ilkov
Affiliation:Technion
Date:18.07.2012
Time:14:30
Location:Lidow 620
Abstract:

Supernovae type Ia (SN Ia) represent one of the most interesting
astrophysical events observed. A SN Ia explosion at its peak can have
luminosity equal to a whole galaxy. We know that they are explosions of
carbon-oxygen white dwarfs (CO WD) but we don’t know what their progenitors
are.
In our work we explore the core-degenerate (CD) scenario in which the
progenitor is a product of a merger between a WD and the core of an
asymptotic giant branch (AGB) star immediately after the common envelope
(CE) phase. We generate a population of stars using a given initial mass
function (IMF) and then follow the evolution of the stars that are in
binaries. We also introduce a novel approach without using the complicated
alpha common envelope prescription. We also don’t make distinction between
the CD and the double degenerate (DD) scenario in our calculation.
Using a simple population synthesis we come to the conclusion that the
combined CD and DD scenarios produce enough systems to match the observed
numbers of SNIa and the ratio between SNIa and core collapse supernovae (CC
SN).