Physics of black hole formation in failed supernovae

  • Author / Creator
    Ivanov, Mario G
  • I present the formation and evolution of the shock wave driven by neutrino losses in failed core-collapse supernovae that form black holes (BHs). Neutrino losses result in a decrease in the gravitational mass, which leads to the formation of an outward shock. The ejected mass and energy vary widely depending on the classification of the progenitor and the equation of state (EOS) of dense matter. Simulating the inner regions of stellar core-collapse, where the energetics of this phenomenon are set, demands a general-relativistic (GR) neutrino radiation hydrodynamic approach. Publicly available codes do not have a large enough dynamic range to simultaneously model the outer stellar regions, where mass ejection occurs, and the inner core. Previous work on this problem has parameterized the evolution of the inner core, treating it as an effective point mass below a cut-off radius. Here we improve this method by simulating the inner core with a time-dependent, spherically symmetric neutrino radiation hydrodynamics code and the outer layers with a Newtonian code that covers the relevant dynamic range. We use the detailed neutrino mass-loss history in the inner core to modify the gravitational mass felt by the outer layers, that ultimately eject mass. We report several results: (i) we find that the ejecta mass and energy can vary by a factor of several depending on the EOS used, with a stiff EOS matching previous parametric results and a softer EOS leading to less ejected mass and lower energies; (ii) red and yellow supergiant stars have energetically bound ejecta when not including hydrogen recombination energy; (iii) increasing the spatial resolution led to converging results for Wolf-Rayet stars; and (iv) we quantitatively, but not qualitatively, modify previous observational predictions.

  • Subjects / Keywords
  • Graduation date
    Spring 2021
  • Type of Item
  • Degree
    Master of Science
  • DOI
  • License
    This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.