Effect of turbulent viscosity on the isothermal collapse of a rotating protostellar cloud

Journal Article · Mon Jul 15 04:00:00 EDT 1985 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/163317· OSTI ID:5190675

Vanajakshi, T C; Jenkins, Jr, A W

A solution to the angular momentum problem in the theory of star formation has not yet been found. Given the observed rotation rates of molecular clouds wherein star formation is presumed to occur, the formation of a central star requires an effective mechanism for redistributing the angular momentum. This paper reports the effect of turbulent viscosity in the isothermal collapse of a 1 M/sub sun/ protostellar cloud with ..cap omega.. = 3.5 x 10/sup -13/ s/sup -1/. Eulerian hydrodynamics is used on a two-dimensional (30 x 30) grid. Cylindrical coordinates and a finite difference approximation are employed to follow the collapse up to approximately two free-fall times, at which time instabilities in the numerical analysis occur. This paper follows closely the approach used by Black and Bodenheimer and compares the results of viscous and nonviscous collapse. Attempts to reproduce the results of Regev and Shaviv, who used a simpler, phenomenological model for turbulent viscosity, are also described and compared with our results. It is found that, in general, turbulent viscosity slows the collapse and leads to overall enhancement of densities at and near the center. However, it is found that an unreasonably large viscous force may be required to suppress the ring completely.

• Research Organization: Department of Physics, North Carolina State University, Raleigh
• OSTI ID: 5190675
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 294:2; ISSN ASJOA
• Country of Publication: United States
• Language: English

Related Subjects

640102* -- Astrophysics & Cosmology-- Stars & Quasi-Stellar
Radio & X-Ray Sources
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ANGULAR MOMENTUM
BOUNDARY CONDITIONS
DENSITY
FLUID MECHANICS
GRAVITATIONAL COLLAPSE
HYDRODYNAMICS
MATHEMATICS
MECHANICS
MOTION
NEBULAE
NUMERICAL ANALYSIS
ORIGIN
PHYSICAL PROPERTIES
PROTOSTARS
ROTATION
STAR EVOLUTION
STARS
TURBULENCE
VISCOSITY