Feb 01, 2018

Pablo Marchant

""Pulsational pair-instability in very close Binaries""

Very massive stars that can retain helium cores in excess of ∼ 35M are predicted to undergo collapse before core-oxygen depletion, leading to thermonuclear explosions. Depending on their mass,these explosions lead either to a complete disruption of the star in a so-called pair-instability supernova (PISN), or a series of energetic pulses and mass loss in a pulsational pair-instability supernova (PPISN) before black hole formation. Although these explosions have not been unambiguously observed, the high mass of the first binary black hole merger detected, GW150914, suggests these explosions can occur with a nearby binary companion present. In this talk, I will discuss how the presence of such a nearby binary companion can alter the properties of a PPISN, leading to the ocurrence of Roche lobe overflow as well as common-envelope events in between pulses. PPISN can also leave signatures in the resulting binary black hole system including eccentricity enhancements and lower black hole spins than expected through direct collapse. Measuring these effects can provide additional clues to the originof merging binary black holes, in particular to distinguish whether their formed through field binary evolution, or through dynamical interactions in dense environments.

Event Details

Date:
Feb 01, 2018

Time:
3:30–5pm

Location:
4421 Sterling Hall

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

Speaker Host:
TBD

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