Strange quark matter in explosive astrophysical systems

TL;DR

This paper develops an equation of state incorporating a quark matter phase transition for use in astrophysical simulations of explosive systems, considering constraints from heavy ion data and pulsar observations, and explores implications for supernovae and hybrid star properties.

Contribution

It introduces a new approach to modeling quark matter in astrophysical systems, integrating a phase transition into a hadronic equation of state compatible with observational data.

Findings

Implementation of a quark phase transition in the equation of state.

Compatibility with heavy ion collision and pulsar data.

Implications for supernova evolution and hybrid star maximum mass.

Abstract

Explosive astrophysical systems, such as supernovae or compact star binary mergers, provide conditions where strange quark matter can appear. The high degree of isospin asymmetry and temperatures of several MeV in such systems may cause a transition to the quark phase already around saturation density. Observable signals from the appearance of quark matter can be predicted and studied in astrophysical simulations. As input in such simulations, an equation of state with an integrated quark matter phase transition for a large temperature, density and proton fraction range is required. Additionally, restrictions from heavy ion data and pulsar observation must be considered. In this work we present such an approach. We implement a quark matter phase transition in a hadronic equation of state widely used for astrophysical simulations and discuss its compatibility with heavy ion collisions and pulsar data. Furthermore, we review the recently studied implications of the QCD phase transition during the early post-bounce evolution of core-collapse supernovae and introduce the effects from strong interactions to increase the maximum mass of hybrid stars. In the MIT bag model, together with the strange quark mass and the bag constant, the strong coupling constant $\alpha_s$ provides a parameter to set the beginning and extension of the quark phase and with this the mass and radius of hybrid stars.