相关论文: Ab initio simulations of accretion disks instabili…

We consider three corrections to the disk sizes estimated at a given frequency using accretion models. They are due to a color correction, a disk truncation at an inner radius larger than the innermost stable circular orbit, and disk winds,…

In this paper we present the global baroclinic instability as a source for vigorous turbulence leading to angular momentum transport in Keplerian accretion disks. We show by analytical considerations and three-dimensional radiation hydro…

We use a series of idealized, numerical SPH simulations to study the formation and evolution of galactic, gas-rich disks forming from gas infall within dark matter halos. The temperature and density structure of the gas is varied in order…

This paper contains a local linear stability analysis for accretion disks under the influence of a global radial entropy gradient beta = - d log T / d log r for constant surface density. Numerical simulations suggested the existence of an…

Analysis and interpretation of the Her X-1 X-ray light curve obtained with the ASM onbord RXTE over the period 1996 February to 2004 September is presented. We report that the features found previously in the averaged X-ray lightcurve are…

We investigate the behaviour of the accretion discs in the outbursts of the low-mass black-hole X-ray binaries (BHXRB), an overview of which we have presented previously. Almost all of the systems in which there are sufficient observations…

In the canonical understanding of transient X-ray sources the accretion during quiescence occurs via a geometrically thin disk in the outer part and via an advection-dominated hot coronal flow/ADAF in the inner part. The inner part…

The large spin-orbit misalignments in the DI Herculis stellar binary system have resolved the decades-long puzzle of the anomalously slow apsidal precession rate, but raise new questions regarding the origin of the obliquities. This paper…

Massive stars can form within or be captured by AGN disks, influencing both the thermal structure and metallicity of the disk environment. In a previous work, we investigated isotropic accretion onto massive stars from a gas-rich,…

We fit the UV/optical lightcurves of the Seyfert 1 galaxy Mrk 817 to produce maps of the accretion disk temperature fluctuations $\delta T$ resolved in time and radius. The $\delta T$ maps are dominated by coherent radial structures that…

We present the results of a multi-wavelength multi-epoch survey of five evolved protoplanetary disks in the IC 348 cluster that show significant infrared variability. Using 3-8micron and 24micron photometry along with 5-40micron…

We report on the first global three-dimensional (3D) MHD simulations of disk accretion onto a rotating magnetized star through the Rayleigh-Taylor instability. The star has a dipole field misaligned relative to the rotation axis by a small…

We examine the small-scale dynamics of black hole accretion disks in which radiation pressure exceeds gas pressure. Local patches of disk are modeled by numerically integrating the equations of radiation MHD in the flux-limited diffusion…

It is shown that the turbulent flow of acoustic waves propagating outward from the inner edge of the disk causes the accretion of the matter onto the center. The exponential amplification of waves takes place in the resonance region, $…

We present various instability mechanisms in the accreting black hole systems which might indicate at the connection between the accretion disk and jet. The jets observed in microquasars can have a persistent or blobby morphology.…

This paper continues a series reporting different aspects of the behaviour of disc galaxy simulations that support spiral instabilities. The focus in this paper is to demonstrate how linear spiral instabilities saturate and decay, and how…

Millimeter sized dust grains experience radial velocities exceeding the gas velocities by orders of magnitude. The viscous evolution of the accretion disk adds disk material onto the central star's convective envelope, influencing its…

This thesis investigates phenomena occurring in black-hole accretion discs which are likely to induce high-frequency quasi-periodic variability. Two classes of pseudo-relativistic theoretical models are studied. The first is based on the…

Rapidly growing black holes are surrounded by accretion disks that make them the brightest objects in the Universe. Their brightness is known to be variable, but the causes of this are not implied by simple disk models and still debated.…

In the disk-mediated accretion scenario for the formation of the most massive stars, gravitational instabilities in the disk can force it to fragment. We investigate the effects of inclination and spatial resolution on observable kinematics…