Core-Corona Decomposition of Very Compact (Neutron) Stars: Accounting for Current Data of XTE J1814-338

TL;DR

This paper models neutron stars using a core-corona decomposition, fitting current data of XTE J1814-338 to understand the core's properties and composition.

Contribution

It introduces a novel core-corona decomposition approach to neutron star modeling, fitting observational data to constrain core parameters.

Findings

Derived core parameters consistent with observational data

Supported the Standard Model matter assumption for the corona

Provided constraints on core composition and structure

Abstract

A core-corona decomposition of compact (neutron) star models was compared with the current mass-radius data of the outlier XTE~J1814-338. The corona (which may also be dubbed the envelope, halo or outer crust) is assumed to be of Standard Model matter, with an equation of state that is supposed to be faithfully known and accommodates nearly all other neutron star data. The core, solely parameterized by its mass, radius and transition pressure, presents a challenge regarding its composition. We derived a range of core parameters needed to describe the current data of XTE J1814-338.