Stellar Core Collapse with Hadron-Quark Phase Transition

TL;DR

This paper investigates how hadron-quark phase transitions affect the core collapse of massive stars, revealing that the transition can influence whether a star explodes as a supernova or collapses into a black hole.

Contribution

It introduces equations of state with hadron-quark phase transitions using the MIT bag model and explores their impact on stellar core collapse outcomes.

Findings

Small bag constant shortens black hole formation interval.

Second bounce can revive shock wave leading to explosion.

Phase transition influences supernova and black hole outcomes.

Abstract

Hadronic matter undergoes a deconfinement transition to quark matter at high temperature and/or high density. It would be realized in collapsing cores of massive stars. In the framework of MIT bag model, the ambiguities of the interaction are encapsulated in the bag constant. Some progenitor stars that invoke the core collapses explode as supernovae, and other ones become black holes. The fates of core collapses are investigated for various cases. Equations of state including the hadron-quark phase transition are constructed for the cases of the bag constant B=90, 150 and 250 MeV fm^{-3}. To describe the mixed phase, the Gibbs condition is used. Adopting the equations of state with different bag constants, the core collapse simulations are performed for the progenitor models with 15 and 40Msolar. If the bag constant is small as B=90 MeV fm^{-3}, an interval between the bounce and black hole formation is shortened drastically for the model with 40Msolar and the second bounce revives the shock wave leading to explosion for the model with 15Msolar.