Spritz: General Relativistic Magnetohydrodynamics with Neutrinos

TL;DR

The paper introduces an enhanced version of the Spritz GRMHD code that incorporates an approximate neutrino leakage scheme, enabling more realistic simulations of astrophysical phenomena like neutron star mergers.

Contribution

It presents the integration of a neutrino leakage scheme into the Spritz code, along with validation tests and implementation of high-order numerical methods for improved accuracy.

Findings

Successful implementation of neutrino leakage scheme in Spritz

Validation through extensive general relativistic tests

Preparation for application to magnetized binary neutron star mergers

Abstract

We here present a new version of the publicly available general relativistic magnetohydrodynamic (GRMHD) code $\texttt{Spritz}$, which now includes an approximate neutrino leakage scheme able to handle neutrino cooling and heating. The leakage scheme is based on the publicly available $\texttt{ZelmaniLeak}$ code, with a few modifications in order to properly work with $\texttt{Spritz}$. We discuss the involved equations, physical assumptions, and implemented numerical methods, along with a large battery of general relativistic tests performed with and without magnetic fields. Our tests demonstrate the correct implementation of the neutrino leakage scheme, paving the way for further improvements of our neutrino treatment and the first application to magnetized binary neutron star mergers. We also discuss the implementation in the $\texttt{Spritz}$ code of high-order methods for a more accurate evolution of hydrodynamical quantities.