Core-Collapse Supernovae Through Cosmic Time

When massive stars (those with at least 8 times the Sun's mass) reach the end of their existence they can explode releasing large quantities of heavy elements that enrich the next generation of stars. Modeling these core-collapse supernovae and their ejecta requires complex and well resolved three-dimensional numerical simulations running on large computers. The abundances of heavy elements (known as 'metals' to astronomers) has increased from none in the very first stars formed after the Big Bang to the Solar-like composition found in recently formed stars in the nearby universe. Supernovae are dependent on the pre-explosion structure of the star, which is dependent on both the stellar mass and the amount of 'metals' in the star. To cover the variation through cosmic time in the stars that explode as supernovae we will compute three well-resolved 3D supernova simulations for low, medium, and high mass exploding stars at each of three 'metallicities' representing the build-up of heavy elements from the primordial zero metallicity to solar metallicity. From these simulations the investigators will extract the properties of the explosions and their ejecta to get a better understanding of the nature of the supernova mechanism and its contributions to the evolution of galaxies through cosmic time.

The investigators will use their multi-physics Chimera code, which includes neutrino radiation hydrodynamics with modern neutrino-matter interactions, general relativistic corrections to multi-pole self-gravity, a dense matter nuclear equation of state, and built-in nuclear networks to compute evolving abundances in the non-equilibrium layers outside the iron-core and in the ejecta. The three simulations of 1-degree resolution will be computed at each metallicity from low (about 10 solar mass), medium (15 solar mass), and high (about 25 solar mass) progenitors found to explode in similar 2D (axisymmetric) simulations. Simulations will be computed at zero, solar, and low metallicities and both direct and post-processed nucleosynthesis will be computed for the ejecta. Additional analyses will produce gravitational wave and neutrino signals that directly probe the central supernova engine.