ABSTRACT In the inner regions of accretion disks around compact objects, the orbital frequency of the gas deviates from the local Keplerian value. For long-wavelength modes in this region, the radial epicyclic frequency κ is higher than the azimuthal frequency Ω. This has significant implications for models of the twin kHz QPOs observed in many neutron-star sources that traditionally identify t...

Dynamics of stationary axisymmetric configuration of the viscous accreting fluids surrounding a non-rotating compact object in final stages of accretion flow is presented here. For the special case of thin disk approximation, the relativistic fluid equations ignoring self-gravity of the disk are derived in Schwarzschild geometry. For two different state equations, two sets of self-consistent an...

This paper presents a study on the effect of glittering and reflective objects with different colors to the output voltagedistance characteristics of Sharp GP2D120 IR Sensor, which operates by employing the principle of single point triangulation. The study was conducted by using a compact disk and plastic materials with four different colors, in which the distance for each of them was measured...

We present spatial and spectral results of ROSAT observations of two galaxies: NGC 4569 and NGC 4303. Both objects are members of the Virgo Cluster and have nearby smaller companions with which they have probably gone through an encounter. Both soft X-ray spectra (0.1–2.4 keV) can be fitted with a two-component model consisting of a power-law component from a non-thermal emission of a compact a...

In a round ball B⊂Rn+1 endowed with an O(n+1)-invariant metric we consider radial function that weights volume and area. We prove compact two-sided hypersurface in B which is stable capillary weighted sense symmetric about some line containing the center of homeomorphic to closed n-dimensional disk. When combined Hsiang symmetrization other stability results this allows deduce interior boundary...

Subsequent to Paper I, the evolution and fragmentation of a rotating magnetized cloud are studied with use of three-dimensional MHD nested-grid simulations. After the isothermal runaway collapse, an adiabatic gas forms a protostellar first core at the center of the cloud. When the isothermal gas is stable for fragmentation in a contracting disk, the adiabatic core often breaks into several frag...

We investigate dust dynamics and evolution during the formation of a protostellar accretion disk around intermediate mass stars via 2D numerical simulations. Using three different detailed dust models, compact spherical particles, fractal BPCA grains, and BCCA grains, we find that even during the early collapse and the first ∼ 10 yr of dynamical disk evolution, the initial dust size distributio...

The Bardeen-Petterson effect around a rapidly-rotating compact object causes a tilted accretion disk to warp into the equatorial plane of the rotating body. Viscous forces cause the accretion flow to divide into two distinct regions an inner aligned accretion disk and an outer tilted accretion disk. The transition between these two occurs at a characteristic radius that depends on the mass and ...

We present the first ground-based near-infrared image of the circumstellar disk around the post-Herbig Ae/Be star HD141569A initially detected with the HST. Observations were carried out in the near-IR (2.2 µm) at the Palomar 200-inch telescope using the adaptive optics system PALAO. The main large scale asymmetric features of the disk are detected on our ground-based data. In addition, we meas...