Related papers: A Possible Origin of kHZ QPOs in Low-Mass X-ray Bi…
The origin of quasi periodic modulations of flux in the kilohertz range (kHz QPOs), observed in low-mass X-ray binaries, is usually assumed to be physically distinct from that of the ``normal branch oscillations'' (NBOs) in the Z-sources.…
We suggest a plausible interpretation for the twin kiloHertz quasi-periodic oscillations (kHz QPOs) in neutron star low-mass X-ray binaries. We identify the upper kHz QPO frequencies to be the rotational frequency and the lower kHz QPOs the…
This paper provides a review of the kilohertz quasi-periodic oscillations in low-mass X-ray binaries recently discovered with NASA's Rossi X-ray Timing Explorer. It contains two tables that are up to date up to October 1st, 1997 with…
Some of the more promising ideas about the origin of the high frequency variability (kHz QPOs) in the observed X-ray emissions of low-mass X-ray binaries are contrasted with less promising ones.
The physical origin of high-frequency QPOs (HFQPOs) in black-hole X-ray binaries remains an enigma despite many years of detailed observational studies. Although there exists a number of models for HFQPOs, many of these are simply "notions"…
We ascribe the interpretation of the twin kilohertz Quasi Periodic Oscillations (kHz QPOs) of X-ray spectra of Low Mass X-Ray Binaries (LMXBs) to MHD Alfven wave oscillations in the different mass density regions of the accreted matter at…
We suggest a possible explanation for the high frequency quasi-periodic oscillations (QPOs) in black hole low mass X-ray binaries. By solving the perturbation general relativistic magnetohydrodynamic equations, we find two stable modes of…
Based on the interpretation of the twin kilohertz Quasi Periodic Oscillations (kHz QPOs) of X-ray spectra of Low Mass X-Ray Binaries (LMXBs) to the Keplerian and the periastron precession frequencies at the magnetosphere-disk of X-ray…
We propose a mechanism to explain the low-frequency QPOs observed in X-ray binary systems and AGNs. To achieve this, we perturbed stable accretion disks around Kerr and EGB black holes at different angular velocities, revealing…
The kilohertz quasi periodic oscillations (QPOs) discovered in several low mass X-ray binaries (LMXBs) by the Rossi X-ray Timing Explorer (XTE) are thought to occur at the orbital frequency in accretion discs whose inner edge corresponds to…
The relativistic precession model for quasi periodic oscillations, QPOs, in low mass X-ray binaries is reviewed. The behaviour of three simultaneous types of QPOs is well matched in terms of the fundamental frequencies for geodesic motion…
We describe kHz QPOs from the hydrodynamical model of accretion disks for LMXB systems. Out of the pair, the higher frequency originates due to the viscous effects of an accretion disk involving the formation of shock, while the lower one…
We study the kilohertz quasi-periodic oscillations (kHz QPOs) in neutron star low mass X-ray binaries (LMXBs) with a new magnetohydrodynamics (MHD) model, in which the compressed magnetosphere is considered. The previous MHD model (Shi \&…
A model of low-frequency quasi-periodic oscillations (LFQPOs) of black hole X-ray binaries (BHXBs) is proposed based on the perturbed magnetohydrodynamic (MHD) equations of accretion disk. It turns out that the LFQPOs frequencies of some…
The observed quasi-periodic oscillations (QPOs) in low-mass X-ray binaries have been suggested to be probably related to the characteristic oscillation modes in the inner part of a relativistic accretion disk. In this paper we study the…
We consider the interpretation of a pair of kHz Quasi Periodic Oscillations (QPOs) in the Fourier spectra of two Low Mass X-Ray Binaries, Sco X-1 and 4U1608-52, hosting an old accreting neutron star. The observed frequency difference of…
We examine whether the two-armed ($m=2$) vertical p-mode oscillations trapped in the innermost region of magnetized accretion disks with finite disk thickness can describe kHz QPOs and HBOs in LMXBs. First, we derive the frequency-frequency…
Low Frequency Quasi-Periodic Oscillations or LF QPOs are ubiquitous in BH X-ray binaries and provide strong constraints on the accretion-ejection processes. Although several models have been proposed so far, none has been proven to…
The kilohertz quasi-periodic oscillations (kHz QPOs) have been found in neutron star low mass X-ray binaries (NS-LMXBs), which present the millisecond timing phenomena close to the surface of the compact objects. We briefly summarize the…
A possible model of twin high-frequency QPOs (HF QPOs) of microquasars is examined. The disk is assumed to have global magnetic fields and to be deformed with a two-armed pattern. In this deformed disk, set of a two-armed ($m=2$) vertical…