Bounds on Neutron-Star Moments of Inertia and the Evidence for General Relativistic Frame Dragging
arXiv:astro-ph/9903415 · doi:10.1103/PhysRevD.61.024009
Abstract
Recent X-ray variability observations of accreting neutron stars may provide the first evidence for frame dragging effects around spinning relativistic objects. Motivated by this possibility and its implications for neutron-star structural properties, we calculate new optimal bounds on the masses, radii, and moments of inertia of slowly rotating neutron stars that show kilohertz quasi-periodic oscillations (QPOs). These bounds are derived under minimal assumptions about the properties of matter at high densities and therefore are largely independent of the unknown equation of state. We further derive a semi-analytical upper bound on the neutron-star moment of inertia without making any assumptions about the equation of state of matter at any density. We use this upper bound to show that the maximum possible nodal precession frequency of an inclined circular orbit around a slowly spinning neutron star is nu_{NP}~45.2 (nu_s/300Hz) Hz, where nu_s is the spin frequency of the neutron star. We conclude that the nodal-precession interpretation of low-frequency QPOs in accreting neutron stars is inconsistent with their inferred spin frequencies or the identification of the highest-frequency QPO with that of a circular Keplerian orbit in the accretion disk.
8 pages, 5 figures, accepted for publication in Phys. Rev. D; references added and minor typos corrected
References in corpus (12)
- Lense-Thirring Precession and QPOs in Low Mass X-Ray Binaries
- Neutron Star Mass Measurements. I. Radio Pulsars
- kHz Quasi Periodic Oscillations in Low Mass X-ray Binaries as Probes of General Relativity in the Strong Field Regime
- Bounds on the Compactness of Neutron Stars from Brightness Oscillations
- On the Amplitude of Burst Oscillations in 4U 1636-54: Evidence for Nuclear Powered Pulsars
- Strong Correlation Between Noise Features at Low Frequency and the Kilohertz QPOs in the X-Ray Binary 4U 1728-34
- Mass-to-Radius Ratio for the Millisecond Pulsar J0437-4715
- Effects of Rapid Stellar Rotation on Equation of State Constraints Derived from Quasi-Periodic Brightness Oscillations
- General-relativistic constraints on the equation of state of dense matter implied by kilohertz quasi-periodic oscillations in neutron-star X-ray binaries
- Discovery of Two Simultaneous Kilohertz QPOs in the Persistent Flux of GX 349+2
- A new instability of accretion disks around compact magnetic stars
- Implications of kHz Quasi-Periodic Brightness Oscillations in X--Ray Binaries for Neutron Star Structure
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- Isolated and Binary Neutron Stars in Dynamical Chern-Simons Gravity
- Phase Transitions in Neutron Stars and Maximum Masses
- Constraining Parity Violation in Gravity with Measurements of Neutron-Star Moments of Inertia
- On the moment of inertia of PSR J0348+0432
- I-Love-Q to the extreme
- Gravitomagnetic effect in magnetized neutron stars
- Frame Dragging Effect on Moment of Inertia and Radius of Gyration of Neutron Star
- Slowly rotating neutron stars and hadronic stars in chiral SU(3) quark mean field model
- Members of the double pulsar system PSR J0737-3039 : neutron stars or strange stars ?