The Burn-UD code for the numerical simulations of the Hadronic-to-Quark-Matter phase transition

TL;DR

Burn-UD is a hydrodynamic simulation code designed to model the complex phase transition from hadronic to quark matter inside neutron stars, providing insights into astrophysical phenomena and QCD regimes.

Contribution

The paper introduces Burn-UD, a novel computational tool that models the micro-physics of the hadronic-to-quark-matter phase transition with applications to neutron star interiors.

Findings

Simulation of flame micro-physics for different equations of state

Analysis of transition scenarios: deflagration, detonation, core-collapse

Potential to constrain QCD non-perturbative regimes

Abstract

Burn-UD is a hydrodynamic combustion code used to model the phase transition of hadronic to quark matter with particular application to the interior of neutron stars. Burn-UD models the flame micro-physics for different equations of state (EoS) on both sides of the interface, i.e. for both the ash (up-down-strange quark phase) and the fuel (up-down quark phase). It also allows the user to explore strange quark seeding produced by different processes including DM annihilation inside neutron stars. The simulations provide a physical window to diagnose whether the combustion process will simmer quietly and slowly, lead to a transition from deflagration to detonation or a (quark) core-collapse explosion. Such an energetic phase transition (a Quark-Nova) would have consequences in high-energy astrophysics and could aid in our understanding of many still enigmatic astrophysical transients. Furthermore, having a precise understanding of the phase transition dynamics for different EoSs could aid further in constraining the nature of the non-perturbative regimes of QCD in general. We hope that Burn-UD will evolve into a platform/software to be used and shared by the QCD community exploring the phases of Quark Matter and astrophysicists working on Compact Stars.