The role of turbulent convection in the primitive solar nebula II: Results

摘要: Abstract Numerical results from a new model of the primordial solar nebula are presented in which convection is assumed to be sole source turbulence that causes evolve. We introduce convective (described detail Paper I this series) and grain opacities computed an improved physical model. The stage prior planetesimal formation gas dust grains mixed homogeneously, but after significant infall matter outer cloud. Vertical structures for thin nebular disk calculated different radii accretion rates assuming vertical hydrostatic thermal equilibrium; radial sequences solutions constructed constant represent quasistatic structures. Some aspects our differ markedly those done previously by Lin co-workers. Our values turbulent efficiency α (10−2 10−4) much lower more sensitive opacity surface density. low result (1) small speeds (≤1% sound speed), will alter computations coagulation sedimentation rates; (2) massive (> 0.1M⊙) becomes gravitationally unstable at (super-Uranian) orbits; (3) “best value” rate (∼1018.5 g sec−1); (4) longer characteristic dispersal time 2 × 106years), may greatly exceed inferred young stellar objects. high sensitivity on density produces inverse rate-surface relationship, implies Lightman-Eardley diffusive instability develops througout steady structure direction, causing disk, least onset, separate into rings. Because gradients neglected base structure, manner evolves finite amplitude unknown, it could prevent reaching altogether. conclude not dominant needed evolve solar/stellar nebulae, fact disruptive mechanism structure.