Andrew W. Steiner

University of Minnesota, Minneaplolis

Nuclear Astrophysics in Two Acts: r-Process Nucleosynthesis in Neutrino-Driven Winds and the Nuclear Symmetry Energy

In the first portion of this talk, we revisit the problem of r-process nucleosynthesis in neutrino driven winds. The boundary conditions for the neutrino-driven wind near the neutron star surface are determined through the novel construction of an "injection region". This allows for a determination of the r-process abundances consistent with hydrodynamic calculations given the properties of the neutron star and the accompanying neutrino emission. In the second portion, the influence of isospin dependence on the structure of neutron stars and nuclei will be explored. We show that: 1) a fit to the equation of state of Akmal, et. al. gives reasonable results for the binding energies and charge radii of doubly-magic nuclei, 2) models with sufficient flexibility to describe variations in the symmetry energy allow for neutron star radii as small as 9 km, and 3) several models do not predict the expected quadratic dependence of the surface energies on the isospin asymmetry.

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