相关论文: Orientation effects in bipolar nebulae: Can disks …
Bipolarity in proto-planetary and planetary nebulae is associated with events occurring in or around their cores. Past infrared observations have revealed the presence of dusty structures around the cores, many in the form of disks.…
IR and mm-wave emission from Herbig Ae/Be stars has produced conflicting conclusions regarding the dust geometry in these objects. We show that the compact dimensions of the mm-wave emitting regions are a decisive indication for disks. But…
Several recent studies have suggested that circumstellar disks in young stellar binaries may be driven into misalignement with their host stars due to secular gravitational interactions between the star, disk and the binary companion. The…
We study the effect of irradiation from two accretion disks (minidisks) around respective black holes of stellar to intermediate masses in a circular binary on the spectrum of a circumbinary disk (CBD) surrounding them. We assume the CBD to…
Current models of binary systems often depend on simplified approach of the radiation field, which are unlikely to accurately capture the complexities of asymmetric environments. We investigate the dynamical and chemical implications of a…
We consider a differentially rotating, 2D stellar disk perturbed by two steady state spiral density waves moving at different patterns speeds. Our investigation is based on direct numerical integration of initially circular test-particle…
The environment of a binary star system may contain two circumstellar disks, one orbiting each of the stars, and a circumbinary disk orbiting about the entire binary. The disk structure and evolution are modified by the presence of the…
UV radiation from OB stars can drive ``external'' photoevaporative winds from discs in clusters, that have been shown to be important for disc evolution and planet formation. However, cluster dynamics can complicate the interpretation of…
The presence of the warm absorber of considerable optical depth is seen in many AGN. We show that this medium may affect significantly the optical/UV spectrum of an AGN by backscattering a fraction of the total radiation flux towards the…
In this paper we study the evolution of viscous and radiative circumstellar disks under the influence of a companion star. We focus on the eccentric {\gamma} Cephei and {\alpha} Centauri system as examples and compare the disk quantities…
We present the results of a Monte Carlo radiative transfer code that calculates the polarization produced by multiple Thomson scattering and variable absorptive opacity in a circumstellar disk around one component of a close detached binary…
Some effects of irradiation on time-dependent accretion-disk models for black hole X-ray novae are presented. Two types of irradiation are considered: direct irradiation from the inner hot disk and indirect irradiation as might be reflected…
I model the effect of rapid stellar rotation on a planet's insolation. Fast-rotating stars have induced pole-to-equator temperature gradients (known as gravity-darkening) of up to several thousand Kelvin that affect the star's luminosity…
A conducting disk significantly changes the generation of the electromagnetic radiation excited by the rotation of the magnetic field frozen to a star. Due to the reflection of waves from a disk there appear waves propagating toward a star,…
Interstellar dust grains efficiently absorb and scatter UV and optical radiation in galaxies, and therefore can significantly affect the apparent structure of spiral galaxies. We discuss the effect of dust attenuation on the observed…
Disks are ubiquitous in stellar astronomy, and play a crucial role in the formation and evolution of stars. In this contribution we present an overview of the most recent results, with emphasis on high spatial and spectral resolution. We…
We present 2-D radiation transfer models of Class I Protostars and show the effect of including more realistic geometries on the resulting spectral energy distributions and images. We begin with a rotationally flattened infalling envelope…
We explore test particle orbits in the orbital plane of eccentric stellar binary systems, searching for ``invariant loops'': closed curves that change shape periodically as a function of binary orbital phase as the test particles in them…
Large dips in the brightness for a number of stars have been observed, for which the tentative explanation is occultation of the star by a transiting circumplanetary disk or ring system. In order for the circumplanetary disk/rings to block…
At the end of their lives low mass stars such as our Sun lose most of their mass. The resulting planetary nebulae show a wide variety of shapes, from spherical to highly bipolar. According to the generalized interacting stellar winds model,…