Surface Emission from Neutron Stars and Implications for the Physics of their Interiors

TL;DR

This paper reviews how surface emissions from neutron stars reveal critical insights into their internal structure, composition, and magnetic fields, advancing our understanding of matter under extreme conditions.

Contribution

It provides a comprehensive overview of the physics governing neutron star surface emissions and summarizes observational constraints on their internal properties.

Findings

Constraints on neutron star radii from spectral analysis

Insights into core and crust composition from thermal luminosity evolution

Magnetic field topology inferred from pulsation profiles

Abstract

Neutron stars are associated with diverse physical phenomena that take place in conditions characterized by ultrahigh densities as well as intense gravitational, magnetic, and radiation fields. Understanding the properties and interactions of matter in these regimes remains one of the challenges in compact object astrophysics. Photons emitted from the surfaces of neutron stars provide direct probes of their structure, composition, and magnetic fields. In this review, I discuss in detail the physics that governs the properties of emission from the surfaces of neutron stars and their various observational manifestations. I present the constraints on neutron star radii, core and crust composition, and magnetic field strength and topology obtained from studies of their broadband spectra, evolution of thermal luminosity, and the profiles of pulsations that originate on their surfaces.