(Received February 7, 1977)
The gravitational, axisymmetric and adiabatic collapse of rotating gas clouds with various initial conditions has been calculated numerically by means of Fluid-In-Cell method. We have assumed that the gas is ideal and its change is adiabatic except for heat production by shock waves and that, initially, a cloud has no motion in a meridional plane and has spherical and polytropic distributions of mass and temperature.
The results of calculations show that a cloud which has initially larger rotational energy bounces more easily, i.e., bounces at lower central density. The bounce occurs first in the direction of the rotation axis and next in direction perpendicular to it. A shock wave generated by the bounce is strong especially in the vicinity of the rotation axis. At first the shock front is nearly parallel to the equatorial plane but it becomes gradually spherical as it propagates outwards.
Calculations have been performed until the mass enclosed inside the shock front becomes as large as 95 percent of the total mass. At this final stage either a rotating spheroidal core or a rotating ring is left in the central region; a ring is formed if initially a cloud is rotating more rapidly, less centrally condensed and at lower temperature.
URL :
http://ptp.ipap.jp/link?PTP/58/536/
DOI : 10.1143/PTP.58.536