Stellar evolution with arbitrary rotation laws. IV. Survey of zero-age main-sequence models

A variety of fully two-dimensional, rotating zero-age main-sequence models are presented. The models include four rotation rates for each of five masses between 3 and 20 M-.. The sequence of models for each mass might be regarded as having one small, one moderate, and two fairly rapid rotations. The convective core rotation law and overshooting are determined by two-dimensional, fully implicit hydrodynamic calculations. All models exhibit convective core overshooting. The slowly rotating models show primarily radial convective motion, while the instantaneous flow patterns of the more rapidly rotating models show that the motion is primarily parallel to the rotation axis. The resulting core rotation rate may be fitted by a power law in the distance from the rotation axis, with a cutoff at small distances from the axis, at least for the moderately and rapidly rotating models. The rotation law in the radiative region external to the convective core was chosen to be uniform for the first models calculated, but some models with negative power laws were constructed. These showed that the power law could not be too steep, or the model developed a density inversion near the rotation axis because the pressure gradient must essentially balance the rotational variation, since the gradient of the gravitational potential is too shallow to aid significantly in the balance.