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TAPIR Seminar

Friday, May 24, 2024
2:00pm to 3:00pm
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Online and In-Person Event
Double White Dwarf Binaries, their explosions and their survivors
Sunny Wong, Graduate Student, Department of Physics, UCSB,

In person: 370 Cahill. To Join via Zoom: 868 5298 8404

ABSTRACT: Type Ia supernovae result from the explosion of a carbon-oxygen white dwarf accreting mass from a binary companion, whose nature remains elusive. In the double detonation scenario, a donor star transfers helium-rich material to an accretor white dwarf, leading to the detonation of the helium shell and the subsequent detonation of the carbon core of the accretor.  I will describe new models of mass transfer from a partially degenerate helium white dwarf onto a carbon-oxygen white dwarf, and highlight their likely outcome as double-detonation type Ia supernovae. 

Following the explosion, the donor star leaves at its orbital velocity of over 1000 km/s. To date, seven such hypervelocity stars have been discovered from Gaia data. They show inflated radii and metal-polluted atmospheres. I will present new 3D hydrodynamical simulations modeling the interaction between the donor star and the supernova ejecta, and show that the post-shock properties of the donor star agree well with one of the best-studied hypervelocity stars. I will also discuss how much material is stripped from the donor and where it resides within the expanding supernova ejecta.

For more information, please contact JoAnn Boyd by phone at 626-395-4280 or by email at [email protected].