Accretion- and nuclear-powered phenomena in neutron stars with millisecond spin periods
type: CreativeWork
description: "Analysis of observations of the X-ray emission produced by accreting neutron stars with millisecond spin periods can provide important information about the masses M and radii R of neutron stars, thereby yielding uniquely valuable information about the still uncertain properties of cold matter at several times the density of nuclear matter; about the evolution of neutron star magnetic fields and spin rates; and about the physics of accretion onto these stars, which are found in close, low-mass binary star systems. Avenues for obtaining this information include modeling the accretion- and nuclear-powered millisecond X-ray brightness oscillations produced by some of these stars and the spectra of their nuclear-powered emission, and then comparing these models with high-quality X-ray data. In this thesis, I explore the so-called ""nearly aligned moving spot model"" that has been proposed to explain many of the observed properties of the accretion-powered millisecond X-ray brightness oscillations produced by some accreting neutron stars in close, low-mass binary star systems and compare the properties this model predicts with the observed properties of these stars. I also study the accuracy and precision with which M and R can be determined by analyzing energy-resolved waveforms of the X-ray brightness oscillations seen during some of the thermonuclear X-ray bursts produced by some of these neutron stars. Finally, I describe how comparison of high-precision measurements of X-ray burst spectra with the spectra predicted by high-precision model atmosphere calculations can be used to constrain M and R. I find that many observed properties of the accretion-powered millisecond X-ray oscillations can be successfully explained by a model in which the X-ray emitting areas on the neutron star surface are close to the star's rotation pole but wander. I find that M and R can be tightly constrained by analyzing energy-resolved X-ray burst oscillation waveform data measured by a fu…
abstract: "Analysis of observations of the X-ray emission produced by accreting neutron stars with millisecond spin periods can provide important information about the masses M and radii R of neutron stars, thereby yielding uniquely valuable information about the still uncertain properties of cold matter at several times the density of nuclear matter; about the evolution of neutron star magnetic fields and spin rates; and about the physics of accretion onto these stars, which are found in close, low-mass binary star systems. Avenues for obtaining this information include modeling the accretion- and nuclear-powered millisecond X-ray brightness oscillations produced by some of these stars and the spectra of their nuclear-powered emission, and then comparing these models with high-quality X-ray data. In this thesis, I explore the so-called ""nearly aligned moving spot model"" that has been proposed to explain many of the observed properties of the accretion-powered millisecond X-ray brightness oscillations produced by some accreting neutron stars in close, low-mass binary star systems and compare the properties this model predicts with the observed properties of these stars. I also study the accuracy and precision with which M and R can be determined by analyzing energy-resolved waveforms of the X-ray brightness oscillations seen during some of the thermonuclear X-ray bursts produced by some of these neutron stars. Finally, I describe how comparison of high-precision measurements of X-ray burst spectra with the spectra predicted by high-precision model atmosphere calculations can be used to constrain M and R. I find that many observed properties of the accretion-powered millisecond X-ray oscillations can be successfully explained by a model in which the X-ray emitting areas on the neutron star surface are close to the star's rotation pole but wander. I find that M and R can be tightly constrained by analyzing energy-resolved X-ray burst oscillation waveform data measured by a fu…
author: Lo, Ka-Ho
language: en
keywords: neutron stars, dense matter, equation of state, bursts, millisecond pulsars, Large Observatory for X-ray Timing (LOFT)
date published: 2013-08-22T16:38:59Z
date modified: 2026-07-22T22:25:34Z
provider: University of Illinois - Urbana-Champaign
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: University of Illinois at Urbana-Champaign

PropertyValue
property ID: Handle
value: http://hdl.handle.net/2142/45397