Rapid X-ray variability

M Van der Klis - Cambridge Astrophysics Series, 2006 - cambridge.org
One of the principal motivations for studying X-ray binaries is that accretion onto neutron
stars and black holes provides a unique window on the physics of strong gravity and dense …

An x-ray periodicity of∼ 1.8 hr in narrow-line seyfert 1 galaxy mrk 766

P Zhang, P Zhang, J Yan, Y Fan… - The Astrophysical …, 2017 - iopscience.iop.org
In the narrow-line Seyfert 1 galaxy Mrk 766, a quasi-periodic oscillation (QPO) signal with a
period of∼ 6450 s is detected in the XMM-Newton data collected on 2005 May 31. This QPO …

QPOs in Compact Sources as a Nonlinear Hydrodynamical Resonance: Determining Spin of Compact Objects

AR Das, B Mukhopadhyay - The Astrophysical Journal, 2023 - iopscience.iop.org
The origin of wide varieties of quasiperiodic oscillations (QPOs) observed in compact
sources is still not well established. Its frequencies range from millihertz to kilohertz …

An X-ray high-frequency quasi-periodic oscillation in NGC 1365

YK Yan, P Zhang, QZ Liu, Z Chang, GC Liu… - Astronomy & …, 2024 - aanda.org
This study presents the detection of a high-frequency quasi-periodic oscillation (QPO) in the
Seyfert galaxy NGC 1365 based on observational data obtained by XMM-Newton in January …

Upper-twin-peak quasiperiodic oscillation in x-ray binaries and the energy from tidal circularization of relativistic orbits

C Germanà - Physical Review D, 2017 - APS
High frequency quasiperiodic oscillations (HF QPOs) detected in the power spectra of low
mass x-ray binaries (LMXBs) could unveil the fingerprints of gravitation in the strong field …

Acoustic perturbations on steady spherical accretion in Schwarzschild geometry

T Naskar, N Chakravarty, JK Bhattacharjee… - Physical Review D …, 2007 - APS
The stationary background flow in the spherically symmetric infall of a compressible fluid,
coupled to the space-time defined by the static Schwarzschild metric, has been subjected to …

An X-Ray High-Frequency QPO in NGC 1365

Y Yan, P Zhang, Q Liu, Z Chang, G Liu, J Yan… - arxiv preprint arxiv …, 2024 - arxiv.org
This study presents the detection of a high-frequency Quasi-Periodic Oscillation (QPO) in the
Seyfert galaxy NGC 1365, based on observational data obtained by the XMM-Newton in …

Spherical accretion: the influence of inner boundary and quasi-periodic oscillations

P Dhang, P Sharma… - Monthly Notices of the …, 2016 - academic.oup.com
Bondi accretion assumes that there is a sink of mass at the centre–which in the case of a
black hole (BH) corresponds to the advection of matter across the event horizon. Other stars …

A model finding a new Richardson potential with different scales for confinement and asymptotic freedom, by fitting the properties of Δ++ and Ω−

M Bagchi, M Dey, S Daw, J Dey - Nuclear Physics A, 2004 - Elsevier
Phenomenological Richardson potential has built in asymptotic freedom (AF in short) and
confinement, with only one parameter Λ in the potential. But it is known that the scales of AF …

Modelling the time-resolved quasi-periodic oscillations in active galactic nuclei

TK Das, B Czerny - Monthly Notices of the Royal Astronomical …, 2011 - academic.oup.com
The observation of the bright Seyfert 1 galaxy RE J1034+ 396 is believed to demonstrate a
drift in the central period of the quasi-periodic oscillation (QPO) linearly correlated with the …