Bulk Viscous Damping of Density Oscillations in Neutron Star Mergers

Particles

卷:3

Arus Harutyunyan¹  Mark Alford²  Armen Sedrakian³ 

[1] Byurakan Astrophysical Observatory, National Academy of Sciences, Byurakan 0213, Armenia;

[2] Department of Physics, Washington University, St. Louis, MO 63130, USA;

[3] Frankfurt Institute for Advanced Studies, D-60438 Frankfurt am Main, Germany;

关键词: Urca processes;    bulk viscosity;    neutrino-trapping;    density oscillations;    neutron star mergers;    dissipation;   

DOI  :  10.3390/particles3020034

来源: DOAJ

【 摘 要 】

In this paper, we discuss the damping of density oscillations in dense nuclear matter in the temperature range relevant to neutron star mergers. This damping is due to bulk viscosity arising from the weak interaction “Urca” processes of neutron decay and electron capture. The nuclear matter is modelled in the relativistic density functional approach. The bulk viscosity reaches a resonant maximum close to the neutrino trapping temperature, then drops rapidly as temperature rises into the range where neutrinos are trapped in neutron stars. We investigate the bulk viscous dissipation timescales in a post-merger object and identify regimes where these timescales are as short as the characteristic timescale ∼10 ms, and, therefore, might affect the evolution of the post-merger object. Our analysis indicates that bulk viscous damping would be important at not too high temperatures of the order of a few MeV and densities up to a few times saturation density.

【 授权许可】

Unknown