Protostellar disks

In the case of nonmagnetic collapse of a spherical cloud (Yorke and Bodenheimer, 1999), the protostar that forms is orbited by a protostellar disk with a similar mass. When angular momentum is transported outward by assumed gravitational torques, and therefore mass is transported inward onto the protostar, the amount of mass remaining in the disk is still so large that most of this matter must eventually be accreted by the protostar through other processes. Hence, the disk at this phase must still be considered a protostellar disk, not a relatively late phase, protoplanetary disk where any objects which form have some hope of... 

Rapid mass and angular momentum transport. Models of the growth of nonaxisymmetry during the collapse and formation of protostellar disks show that large-scale bars and spirals can form with the potential to transfer most of the disk angular momentum outward on timescales as short as 1,000 yr to 0.1 Myr (Boss, 1989), sufficiently fast to allow protostellar disks to transport the most of their mass inward onto the protostar and thereby evolve into protoplanetary disks. 

Some progress has been made in two-dimensional hydrodynamic models of a thick disk evolving under the action of a globally defined alpha viscosity, representing the effects of torques in a marginally gravitationally unstable disk (Yorke and Bodenheimer, 1999), but in these models the evolution eventually slows down and leaves behind a fairly massive protostellar disk after 10 Myr. 

Yorke H. W. and Bodenheimer P. (1999) The formation of protostellar disks III. The influence of gravitationally induced angular momentum transport on disk structure and appearance. Astrophys. J. 525, 330-342. 

Giant planet formation using shallow water simulations of a gaseous protostellar disk was investigated by Zajac, Ingersoll and Dowling, 1991 [371]. They considered vortices in Jupiter s atmosphere. High pressure vortices form spontaneously there and they are stable in an unstable shear flow. They rotate opposite to the sense of... 

Codella and Palla, 1995 [71] reported on a search for water masers in protostellar disks. 160 IRAS sources were selected which define high-mass star forming regions. Water maser emission was found in 11 sources of this sample. This could mean that the population of OB-stars was overestimated by 50%. 

The water maser emission associated with the infrared centers IRS 1 and IRS 3 of the NGC 207 HR star-forming region was studied by Seth, Greenhill, and Holder, 2002 [305]. They used water masers as tracers for protostellar disks. NGC 2027 is a reflection nebula in the constellation of Orion. 

Zajac, B., IngersoU, A.R, Dowling, T.E. Giant planet formation using shallow water simulations of a gaseous protostellar disk. In Bulletin of the American Astronomical Society, vol. 23,p. 1231 (1991)... 

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