High Frequency QPOs in Neutron Stars and Black Holes: Probing Dense Matter and Strong Gravitational Fields
نویسنده
چکیده
Quasi-periodic oscillations (QPOs) have been discovered in the X-ray emission of many neutron stars and black holes. The QPOs with frequencies ∼> 300 Hz are thought to be produced near the surfaces of neutron stars and the event horizons of black holes. I first summarize some of the most important properties of the QPOs seen in neutron star and black hole systems. I then review some of the models that have been proposed and compare them with observational data. Finally, I describe how these QPOs can be used to determine the properties of dense matter and strong gravitational fields.
منابع مشابه
The Physics of Khz Qpos—strong Gravity's Coupled Anharmonic Oscillators
We explain the origin of the puzzling high frequency peaks (QPOs) in the variability power spectra of accreting neutron stars and black holes as a non-linear 1:2 or 1:3 resonance between orbital and radial epicyclic motion. These resonances are present because the gravitational field deviates strongly from a Newtonian 1/r potential. Our theory agrees with the recently reported observations of t...
متن کاملAccreting neutron stars, black holes, and degenerate dwarf stars.
During the past 8 years, extended temporal and broadband spectroscopic studies carried out by x-ray astronomical satellites have led to the identification of specific compact x-ray sources as accreting neutron stars, black holes, and degenerate dwarf stars in close binary systems. Such sources provide a unique opportunity to study matter under extreme conditions not accessible in the terrestria...
متن کاملRapid X-Ray Variability of Neutron Stars in Low-Mass Binary Systems
The dramatic discovery with the Rossi X-Ray Timing Explorer satellite of remarkably coherent ∼300–1200 Hz oscillations in the X-ray brightness of some sixteen neutron stars in low-mass binary systems has spurred theoretical modeling of these oscillations and investigation of their implications for the neutron stars and accretion flows in these systems. High-frequency oscillations are observed b...
متن کاملForced oscillations in relativistic accretion disks and QPOs
In this work we explore the idea that the high frequency QPOs observed in LMXBs may be explained as a resonant coupling between the neutron star spin and epicyclic modes of accretion disk oscillations. We propose a new model for these QPOs based on forced oscillations induced in the accretion disk due to a stellar asymmetric rotating gravitational or magnetic field. It is shown that particles e...
متن کاملProbing Black Holes and Relativistic Stars with Gravitational Waves
In the coming decade, gravitational waves will convert the study of general relativistic aspects of black holes and stars from a largely theoretical enterprise to a highly interactive, observational/theoretical one. For example, gravitational-wave observations should enable us to observationally map the spacetime geometries around quiescient black holes, study quantitatively the highly nonlinea...
متن کامل