In this research, we study how a finite-temperature nuclear equation of state suitable for astrophysical simulations impacts the oscillation modes of neutron stars. We chose the Shen equation of state (EOS) because it accurately describes both stable and unstable nuclei as well as nuclear incompressibilities. I modified the existing MHD code at BYU, the HAD code, to call a lookup table for the Shen EOS for use at run time, and added a Newton-Raphson method algorithm to convert conserved variables to primitive variables. The algorithm was tested and verified by evolving a stable neutron star for several dynamical times and evolving the same star at different resolutions. The normal mode frequency of the neutron star with the Shen EOS was measured and compared to those for neutron stars with an ideal gas EOS found by Font et. al. We found that the fundamental mode of the neutron star using the Shen EOS was slightly larger than that of the ideal gas EOS. This difference is due to the Shen EOS producing stars that are stiffer, increasing the sound speed.
College and Department
Physical and Mathematical Sciences; Physics and Astronomy
BYU ScholarsArchive Citation
Draper, Christian D., "Impact of a Finite-Temperature Equation of State on Neutron Stars" (2011). Theses and Dissertations. 2603.
neutron star, equation of state, numerical relativity, finite-temperature