On the formation of strange quark stars from supernova in compact binaries

TL;DR

This paper investigates the potential formation of strange quark stars from supernova explosions in binary systems, using numerical simulations to show how accretion can induce quark matter deconfinement in neutron stars.

Contribution

It introduces a novel scenario where supernova-induced accretion in binaries could lead to strange quark star formation, supported by detailed numerical modeling.

Findings

Accretion during supernova can increase core density in neutron stars.

Density increase may trigger quark matter deconfinement.

Possible formation pathway for strange quark stars in binaries.

Abstract

Strange quark stars (SQSs), namely compact stars entirely composed of deconfined quark matter, are characterized by similar masses and compactness to neutron stars (NSs) and have been theoretically proposed to exist in the Universe since the 1970s. However, multiwavelength observations of compact stars in the last 50 years have not yet led to an unambiguous SQS identification. This article explores whether SQSs could form in the supernova (SN) explosion of an evolved star (e.g., carbon-oxygen, or Wolf-Rayet) occurring in a binary with the companion being a neutron star (NS). The collapse of the iron core of the evolved star generates a newborn NS and the SN explosion. Part of the ejected matter accretes onto the NS companion as well as onto the newborn NS via matter fallback. The accretion occurs at hypercritical (highly super-Eddington) rates, transferring mass and angular momentum to the stars. We present numerical simulations of this scenario and demonstrate that the density increase in the NS interiors during the accretion process may induce quark matter deconfinement, suggesting the possibility of SQS formation. We discuss the astrophysical conditions under which such a transformation may occur and possible consequences.