Heidelberg 2022 – wissenschaftliches Programm

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EP: Fachverband Extraterrestrische Physik

EP 1: Astrophysics

EP 1.5: Vortrag

Montag, 21. März 2022, 15:15–15:30, EP-H1

Core-Collapse Simulations of Very Massive Star: Gravitational Collapse, Black-hole Formation, and Beyond — •Ninoy Rahman — GSI Helmholtz Centre for Heavy Ion Research

We investigate the final gravitational collapse of rotating and non-rotating pulsational pair-instability supernova progenitors with zero-age-main-sequence masses of 60, 80, and 115 M_⊙ and iron cores between 2.37 M_⊙ and 2.72 M_⊙ by 2D (axi-symmetric) hydrodynamics simulations. Using the general relativistic NADA-FLD code with neutrino transport allows us to follow the evolution beyond the moment when the transiently forming neutron star (NS) collapses to a black hole (BH), which happens in all cases. Because of high neutrino luminosities and mean energies, neutrino heating leads to shock revival before BH formation in all cases except in the rapidly rotating 60 M_⊙ model, where centrifugal effects support a higher NS mass but reduce the neutrino-heating rate by roughly a factor of two compared to the non-rotating counterpart. After BH formation the neutrino luminosities drop steeply but continue on a 1–2 orders of magnitude lower level for several 100 ms because of aspherical accretion of neutrino and shock-heated matter, before the ultimately spherical collapse of the outer progenitor shells suppresses the neutrino emission to negligible values. In all shock-reviving models BH accretion swallows the entire neutrino-heated matter and the diagnostic explosion energies decrease to zero within a few seconds latest. Nevertheless, the shock or a sonic pulse move outward and may trigger mass loss, which we estimate by long-time simulations with the Prometheus code.