A three-dimensional model for molecular cloud collapse and protostellar formation

Thesis/Dissertation · Tue Jan 01 04:00:00 EST 1991

OSTI ID:5259220

Myhill, E A

A three-dimensional Cartesian code was developed to model molecular cloud collapse and protostellar formation. The basic Eulerian scheme employs second-order accurate finite difference methods to advance the fluid variables in time. The hydrodynamic equations governing the collapse contain the effects of self-gravity, rotation, and radiative transfer. Poisson's equation is solved with Green's functions and Fourier transforms, and the Eddington approximation is used to handle radiative transfer. Six collapse calculations were made of initially centrally condensed molecular cloud cores. Two initial density profiles, {rho} {alpha} r{sup {minus}1} and {rho} {alpha} r{sup {minus}2}, were considered. Half of the clouds began the collapse with solid body rotation, while the rest of the models were assigned a differential rotation profile consistent with conservation of angular momentum during core condensation. The results indicate that the fragmentation is possible in molecular cloud cores that begin gravitational collapse with r{sup {minus}1} or r{sup {minus}2} density distributions if the initial conditions also include differential rotation. Cores that collapse with initial uniform rotation, however, do not appear to produce binary fragments.

• Research Organization: California Univ., Los Angeles, CA (United States)
• OSTI ID: 5259220
• 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
CLOUDS
MATHEMATICAL MODELS
MOLECULES
MOTION
PROTOSTARS
ROTATION
STAR EVOLUTION
THREE-DIMENSIONAL CALCULATIONS