Large Eddy Simulations of Magnetized Mergers of Neutron Stars with Neutrinos

TL;DR

This paper presents advanced large eddy simulations of magnetized neutron star mergers incorporating neutrino physics, magnetic field amplification, and realistic equations of state, to improve modeling of multi-messenger signals.

Contribution

It extends the MHDuet code to include neutrino cooling and large eddy simulations, enhancing the realism of neutron star merger modeling.

Findings

Code accurately simulates isolated and binary neutron stars.

Includes neutrino cooling via leakage scheme.

Captures magnetic field amplification during mergers.

Abstract

Neutron star mergers are very violent events involving extreme physical processes: dynamic, strong-field gravity, large magnetic field, very hot, dense matter, and the copious production of neutrinos. Accurate modeling of such a system and its associated multi-messenger signals, such as gravitational waves, short gamma ray burst, and kilonova, requires the inclusion of all these processes, and is increasingly important in light of advancements in multi-messenger astronomy generally, and in gravitational wave astronomy in particular (such as the development of third-generation detectors). Several general relativistic codes have been incorporating some of these elements with different levels of realism. Here, we extend our code MHDuet, which can perform large eddy simulations of magnetohydrodynamics to help capture the magnetic field amplification during the merger, and to allow for realistic equations of state and neutrino cooling via a leakage scheme. We perform several tests involving isolated and binary neutron stars demonstrating the accuracy of the code.