The formation of a protostar is accompanied by a structure that consists of an accretion disk, a bipolar outflow, and a surrounding envelope. The disk is at the stage of separation into protoplanetary rings. The disk plane is warped like the brim of a hat. The disk is 27 AU in diameter...
The possible diameter and thickness of an accretion disk around a collapsed secondary in Cygnus X-1 are investigated in order to investigate the applicability of standard accretion disk models to optical polarization and H beta photometry observations. For a disk extending at least to Paczynski's li...
In this lesson, learn about accretion disks, and how and why they form in our universe. Then discover the important role they play in the discovery...
We find that (1) inward accretion occurs mostly in the upper magnetically dominated regions of the disk at z R, similar to predictions from some previous analytical work and the "coronal accretion" flows found in GRMHD simulations. (2) A quasi-static global field geometry is established in ...
models of the explosion have been tested and developed. I review nine novae for which Swift has made a significant impact; these have shown the signature of the components in the interacting binary system in addition to the white dwarf: the re-formedaccretion disk, thecompanion starand itsstell...
Methods. We modeled the light curve through an inverse method, using a theoretical light curve of the binary system that considers the light curve contribution of both stars and the accretion disk of the hot star to obtain the fundamental parameters. To constrain the main stellar parameters, the...
A model of a thin polytropic disk accretion onto a polytropic star through a polytropic boundary layer is analyzed and a one-parameter series of models is calculated with the stellar angular velocity varying from small to somewhat supercritical values along the series. It is demonstrated that there...
For others, the stream circulates to form an accretion disk about the companion, which is heated both by turbulent viscosity and the impact of the stream in its periphery. These systems typically show inverted mass ratios, in that the more evolved star has the lower mass. They have masses ...
Results of an investigation of the radial-azimuthal instability properties of an isothermal alpha-viscosity accretion disk around a black hole are reported. It is shown that, even in the case of alpha = 0, an acoustic instability is present in both inner and outer regions of the disk for rad...
suites by firmground and eventually hardground omission suites, recording a number of discrete ichnocoenoses. Nevertheless, such periods of sediment starvation, and omission may be a response to Milankovitch-typeclimate cyclesand of allocyclic origin (e.g.,Savrda and Bottjer, 1989;Savrda, 1995)...