Collapse and fragmentation of rotating, adiabatic clouds
Abstract
A numerical hydrodynamics code has been used to calculate the collapse of rotating, adiabatic clouds. The threedimensional nature of the calculation allows the clouds to fragment in the dynamic collapse phase. Clouds with adiabatic exponent of 7/5 and initial cos(2 phi) density variations fragment into binary systems if the initial ratio of thermal to gravitational energy is small (about 0.05). Clouds with higher thermal energy, however, damp the density variation and form nearequilibrium ellipsoids, with ratios of rotational to gravitational energy less than the critical value for dynamic growth of nonaxisymmetry in Maclaurin spheroids. Even with an adiabatic pressure law, dynamic fragmentation of a collapsing cloud is possible, implying for star formation theory that the low thermal energy fragments produced in isothermal collapse calculations may undergo a subsequent dynamic fragmentation in the nonisothermal regime.
 Publication:

The Astrophysical Journal
 Pub Date:
 November 1981
 DOI:
 10.1086/159411
 Bibcode:
 1981ApJ...250..636B
 Keywords:

 Adiabatic Conditions;
 Binary Stars;
 Gravitational Collapse;
 Interstellar Matter;
 Rotating Fluids;
 Stellar Evolution;
 Astronomical Models;
 Computer Programs;
 Density Distribution;
 Fragments;
 Hydrodynamic Equations;
 Astrophysics