Spectral Lines from Rotating Neutron Stars
arXiv:astro-ph/0209225 · doi:10.1086/346197
Abstract
The line profiles from rotating neutron stars are affected by a number of relativistic processes such as Doppler boosts, strong self-lensing, frame-dragging, and the differential gravitational redshift arising from the stellar oblateness. In this Letter, we calculate line profiles taking into account the first two effects, which is accurate for rotation rates less than the breakup frequency. We show that the line profiles are not only broadened and weakened but are also significantly asymmetric, and allow for an independent measurement of both the mass and the radius of the neutron star. Furthermore, we investigate the case when a fraction of the neutron star surface contributes to the emission and find that the line profiles are typically doubly peaked. We discuss the implications of our results for searches for line features in the spectra of isolated neutron stars and X-ray bursters. We finally assess the systematic uncertainties introduced by the line asymmetry in inferring the compactness of neutron stars from the detection of redshifted lines.
8 pages, submitted to The Astrophysical Journal Letters
References in corpus (3)
Cited by in corpus (34)
- Measuring the neutron star equation of state using X-ray timing
- Probes and Tests of Strong-Field Gravity with Observations in the Electromagnetic Spectrum
- EXO 0748-676 Rules out Soft Equations of State for Neutron Star Matter
- Rotating Stars in Relativity
- Quark deconfinement and implications for the radius and the limiting mass of compact stars
- Exposing the Nuclear Burning Ashes of Radius Expansion Type I X-ray Bursts
- Atmosphere Models of Magnetized Neutron Stars: QED Effects, Radiation Spectra, and Polarization Signals
- Surface Emission from Neutron Stars and Implications for the Physics of their Interiors
- Light Curves for Rapidly-Rotating Neutron Stars
- A Ray-Tracing Algorithm for Spinning Compact Object Spacetimes with Arbitrary Quadrupole Moments. I. Quasi-Kerr Black Holes
- Constraints on Neutron Star Parameters from Burst Oscillation Light Curves of the Accreting Millisecond Pulsar XTE J1814-338
- Discovery of the Neutron Star Spin Frequency in EXO 0748-676
- Systematic Uncertainties in the Spectroscopic Measurements of Neutron-Star Masses and Radii from Thermonuclear X-ray Bursts. I. Apparent Radii
- Measurement of neutron star parameters: a review of methods for low-mass X-ray binaries
- Discovery of a 552 Hz burst oscillation in the low-mass X-ray binary EXO 0748-676
- Radiation from rapidly rotating oblate neutron stars
- A Ray-Tracing Algorithm for Spinning Compact Object Spacetimes with Arbitrary Quadrupole Moments. II. Neutron Stars
- Atomic Spectral Features During Thermonuclear Flashes on Neutron Stars
- Rotational Broadening of Atomic Spectral Features from Neutron Stars
- Rotational Corrections to Neutron-Star Radius Measurements from Thermal Spectra
- Formation of Resonant Atomic Lines during Thermonuclear Flashes on Neutron Stars
- The Shapes of Atomic Lines from the Surfaces of Weakly Magnetic Rotating Neutron Stars and Their Implications
- Narrow Atomic Features from Rapidly Spinning Neutron Stars
- The Incompatibility of Rapid Rotation with Narrow Photospheric X-ray Lines in EXO 0748-676
- Non-Detection of Gravitationally Redshifted Absorption Lines in the X-ray Burst Spectra of GS 1826-24
- Spectroscopic Constraints on the Surface Magnetic Field of the Accreting Neutron Star EXO 0748-676
- Understanding High-Density Matter Through Analysis of Surface Spectral Lines and Burst Oscillations from Accreting Neutron Stars
- Search for Redshifted 2.2 MeV Neutron Capture Line From A0535+262 in Outburst
- Gravitational Redshift for Rapidly Rotating Neutron Stars
- Angular momentum transport during X-ray bursts on neutron stars: a numerical general relativistic hydrodynamical study
- On the impact of an intermediate duration X-ray burst on the accretion environment in IGR J17062-6143
- X-ray views of neutron star low-mass X-ray binaries
- The Extreme Physics Explorer and Large Area Micro-Channel Plate Optics
- Influence of the gravitational darkening effect on the spectrum of a hot, rapidly rotating neutron star. II. Iron lines