Three-dimensional Boltzmann-Hydro code for core-collapse in massive stars II. The Implementation of moving-mesh for neutron star kicks

TL;DR

This paper introduces a novel moving-mesh technique for a multi-dimensional Boltzmann-Hydro code that incorporates general relativistic neutrino transfer, improving the accuracy of core-collapse supernova simulations.

Contribution

The paper presents a new moving-mesh method that treats neutrino transfer within a 3+1 GR framework, enhancing the realism of supernova modeling.

Findings

Successfully tracks proto-neutron star motions

Demonstrates the method's effectiveness in test simulations

Advances towards realistic CCSN simulations

Abstract

We present a newly developed moving-mesh technique for the multi-dimensional Boltzmann-Hydro code for the simulation of core-collapse supernovae (CCSNe). What makes this technique different from others is the fact that it treats not only hydrodynamics but also neutrino transfer in the language of the 3+1 formalism of general relativity (GR), making use of the shift vector to specify the time evolution of the coordinate system. This means that the transport part of our code is essentially general relativistic although in this paper it is applied only to the moving curvilinear coordinates in the flat Minknowski spacetime, since the gravity part is still Newtonian. The numerical aspect of the implementation is also described in detail. Employing the axisymmetric two-dimensional version of the code, we conduct two test computations: oscillations and runaways of proto-neutron star (PNS). We show that our new method works fine, tracking the motions of PNS correctly. We believe that this is a major advancement toward the realistic simulation of CCSNe.