Title:	Astrophysics at the Extremes: The Death of Massive Stars
DNr:	SNIC 2018/3-638
Project Type:	SNIC Medium Compute
Principal Investigator:	Evan Patrick O'Connor <evan.oconnor@astro.su.se>
Affiliation:	Stockholms universitet
Duration:	2019-02-01 – 2019-08-01
Classification:	10305
Homepage:	http://www.evanoc.com
Keywords:

Abstract

Astrophysical environments at the extremes play crucial roles in astronomy, as well as being extraordinary laboratories for studying fundamental physics. One of these environments is core-collapse supernovae (CCSNe). A CCSN is an explosion that results when the iron core of a massive star collapses. A small fraction (~1%) of the huge amount of gravitational binding energy released is used to turn the implosion into an explosion that gives an incredibly bright display of optical light. Research in this field, after over 50 years of intense study, is at a turning point in terms of our understanding. Modern simulations of CCSNe (including ones from the code used here) are readily achieving successful explosions, especially in 2D, but also, importantly, in 3D. The progress in the field gives us confidence that we understand the mechanism that causes stars to successfully explode as CCSNe and as such, we now have a unique opportunity to self-consistently test these multidimensional simulations against observations and address several outstanding questions in the field of massive stars. This will be a remarkable step forward from the systematic, but parameterized, studies done in spherical symmetry up until now. We are now in a position to make precision and self-consistent predictions of many CCSN observables such as the explosion energy, success/failure landscape and neutron star and black hole mass distributions. With this allocation we propose to explore the core collapse and explosion phase of 100 stars in 2D using advanced state-of-the-art neutrino transport and hydrodynamical methods. We aim to determine, from self-consistent simulations, which stars successful explode as supernovae and which fail and form black holes across the diverse range of progenitors. The large number of simulations are needed since previous work has shown that the explosion properties and dynamical behavior of stars undergoing core-collapse can dramatically varying with the initial mass of the star. Large systematic studies like this one are needed to help grow our understanding what initial conditions, if any, can predict the outcome. This has been attempted in 1D, but the results are plagued by the lack of the critical multidimensional behavior. We will also make estimates of the final neutron star and black hole mass distributions for use in interpreting current and upcoming gravitational wave observations. These results will allow us to address key questions in the theory of CCSN explosions, such as the red supergiant problem. We will also simulate the evolution of the supernova shock through the progenitor star in order to capture the multidimensional structure of the innermost ejecta. With this, we hope to be able to correlate features in the nebular phase spectra from observations with multidimensional structures in the innermost ejecta. This may lead to constraints on the inner structure of massive stars.