Dynamical and thermal evolution of the quark-nova ejecta

TL;DR

This paper investigates the dynamical and thermal behavior of neutron star crust ejecta in a Quark-Nova, revealing how explosion energy influences relativistic ejection, cooling, and fragmentation into clumps with distinct shapes and sizes.

Contribution

It provides a detailed analysis of the ejecta's evolution, highlighting how phase state affects clump formation and morphology, which was not previously characterized.

Findings

Ejecta achieve Lorentz factors of a few to hundreds.

Clump formation depends on whether the ejecta is liquid or solid.

Clump sizes are approximately 10^4 cm, with shapes varying by phase.

Abstract

We explore the dynamical and thermal evolution of the ejected neutron star crust in a Quark-Nova explosion. Typical explosion energies and ejected crust masses result in relativistic ejection with Lorentz factors of a few to a few hundred. The ejecta undergoes a rapid cooling and stretching resulting in break up into many small pieces (clumps) when the ejecta is only ~ 100 km from the explosion site. The number and size of the clumps depends on whether the breakup occurs in the liquid or solid phase. For these two cases, the clump number is ~ 10^3 (liquid phase) or ~ 10^7 (solid phase) and, at break up, are spherical (size ~ 10^4 cm; liquid phase) or needle shaped (~ 10^4x10^2 cm; solid phase).