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Merging White Dwarfs

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Contact: F.X.Timmes
my one page vitae,
full vitae,
research statement, and
teaching statement.
Spectra of Type Ia Supernovae from Double Degenerate Mergers (mergers II, 2012)
In this article we combine population synthesis, merger, and explosion models with radiation-hydrodynamics light-curve models to study the implications of such a progenitor scenario on the observed Type Ia supernova population. Our standard model, assuming double-degenerate mergers do produce thermonuclear explosions, produces supernova light curves that are broader than the observed type Ia sample. In addition, we discuss how the shock breakout and spectral features of these double-degenerate progenitors will differ from the canonical bare Chandrasekhar-massed explosion models. We conclude with a discussion of how one might reconcile these differences with current observations.


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assumed profile
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x-ray luminosities



Remnants of Binary White Dwarf Mergers (mergers I, 2010)
In this article we carry out a comprehensive smooth particle hydrodynamics simulation survey of double-degenerate white dwarf binary mergers of varying mass combinations in order to establish correspondence between initial conditions and remnant configurations. We find that all but one of our simulation remnants share general properties such as a cold, degenerate core surrounded by a hot disk, while our least massive pair of stars forms only a hot disk. We also find that some of our simulations with massive white dwarfs exhibit helium detonations on the surface of the primary star before complete disruption of the secondary. However, these helium detonations are insufficiently energetic to ignite carbon, and so do not lead to prompt carbon detonations.


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initial conditions matter
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0.8 + 0.8 Msun evolution
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0.8 + 0.8 Msun, final configuration
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0.8 + 0.8 Msun, x-z plane slice
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0.96 + 1.06 Msun, He detonation
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0.64+1.06 Msun, He detonation