Global Modeling of Nebulae with Particle Growth, Drift, and Evaporation Fronts. II. The Influence of Porosity on Solids Evolution

Incremental particle growth in turbulent protoplanetary nebulae is limited by a combination of barriers that can slow or stall growth. Moreover, particles grow massive enough to decouple from the gas are subject inward radial drift which could lead depletion most disk solids before planetesimals form. Compact probably not realistic. Rather, it more likely grains as fractal aggregates may overcome this so-called barrier because they remain coupled than compact equal mass. We model aggregate and compaction viscously evolving solar-like nebula for range intensities $\alpha_{\rm{t}} = 10^{-5}-10^{-2}$. do find less influential porous over much their phase; however, outside water snowline larger masses with Stokes numbers quickly particles, leading rapid drift. As result, out $\sim 10-20$ AU depleted earlier models, but 20$ material retained longer there lower initially. Nevertheless, we conclude even models will lose without intervention some leap-frog planetesimal forming mechanism such Streaming Instability (SI), though conditions SI generally never satisfied, except brief period %for stage around 0.2$ Myr at $\alpha_{\rm{t}}=10^{-5}$.