相关论文: Using precession and quasiperiodic oscillations to…

An accretion disk formed around a supermassive black hole (SMBH) after it disrupts a star is expected to be initially misaligned with respect to the black hole's equatorial plane. This misalignment induces relativistic torques (the…

High frequency quasi-periodic oscillations (HF QPOs) are observed in the X-ray power-density spectra (PDS) of several microquasars and low mass X-ray binaries. Many proposed QPO models are based on oscillations of accretion toroidal fluid…

Quasi-periodic oscillations (QPOs) observed in the power spectrum of black holes are unique observational probes to the background spacetime since they can be directly related to the timescales associated with the motion of matter orbiting…

We present the results of our studies on accretion disks in the proximity of astrophysical black holes. These disks can be of varying degrees of opacity, geometrical shapes, sizes, and volumes. The central compact object is a Schwarzschild…

Quasi-periodic oscillations, often present in the power density spectrum of accretion disk around black holes, are useful probes for the understanding of gravitational interaction in the near-horizon regime of black holes. Since the…

We analyze in detail the spin precession equations in binary black hole systems, when the tidal torque on a Kerr black hole due to quadrupole-monopole coupling is taken into account. We show that completing the precession equations with…

This paper continues the analysis of a set of general relativistic 3D MHD simulations of accreting tori in the Kerr metric with different black hole spins. We focus on bound matter inside the initial pressure maximum, where the…

Inner accretion disc around a black hole provides a rare, natural probe to understand the fundamental physics of the strong gravity regime. A possible tilt of such a disc, with respect to the black hole spin equator, is important. This is…

An exact expression for the rate of dragging of inertial frames (Lense-Thirring (LT) precession) in a general stationary spacetime, is derived without invoking the weak field approximation. This expression, when used for the Kerr metric,…

A number of black hole X-ray transients show quasi-periodic oscillations (QPOs) in the optical (ultraviolet) and X-ray bands at the same frequency, which challenge models for production of radiation at these wavelengths. We propose a model…

We discuss the solution of accretion disk when the black hole is chosen to be rotating. We study, how the fluid properties get affected for different rotation parameters of the black hole. We know that no cosmic object is static in…

An accretion disk around a rotating magnetized star is subjected to magnetic torques which induce disk warping and precession. These torques arise from interactions between the stellar field and the induced surface currents on the disk.…

In this paper, we first investigate some aspects of frame dragging in strong gravity. The computations are carried out for the Kerr black hole and for the rotating Janis-Newman-Winicour solution, that is known to have a naked singularity on…

We present results of several numerical simulations of two dimensional axi-symmetric accretion flows around black holes using the Smoothed Particle Hydrodynamics (SPH). We consider both stellar black holes and as well as super-massive black…

In this paper, we investigate for the first time the quasi-periodic oscillations (QPOs) that arise as a result of halting the Bondi-Hoyle-Lyttleton (BHL) accretion mechanism around a Kerr black hole. Unlike previous studies, which focused…

Using two-dimensional hydrodynamic simulations, we investigate the stability of shocked accretion flows around black holes under non-axisymmetric perturbations. By systematically exploring the parameter space of specific energy and angular…

We study the time dependent properties of sub-Keplerian viscous accretion flow around the black holes. We find that rotating matter feels centrifugal barrier on the way towards the black holes and eventually, shock transition is triggered…

The precession phenomenon of the jet in a gamma-ray burst (GRB) is a key probe of the physics of the central engine. Previous studies generally assumed a fixed precession period when analysing the temporal profiles in GRBs; however, the…

Low-frequency quasi-periodic oscillations (LFQPOs) have been routinely observed in black hole X-ray binaries (BHXRBs). These LFQPOs can be explained by axisymmetric shock oscillation in accretion flow around a rotating black hole. We…

Low and intermediate frequency quasi-periodic oscillations (QPOs) in black hole candidates are believed to be due to oscillations of the Comptonizing regions in an accretion flow. Assuming that the general structure of an accretion disk is…