Constrained Evolution of a Radially Magnetized Protoplanetary Disk: Implications for Planetary Migration

摘要: We consider the inner $\sim$ AU of a protoplanetary disk (PPD), at stage where angular momentum transport is driven by mixing radial magnetic field into from T-Tauri wind. Because profile imposed well constrained, deterministic calculation mass flow becomes possible. The vertical profiles obtained in Paper I imply stronger magnetization disk, faster accretion, and secular depletion material. Inward solids allows to maintain broad optical absorption layer even when grain abundance too small suppress its ionization. Thus PPD may show strong middle-to-near infrared spectral excess while departs radically minimum-mass solar nebula. surface density buffered $\sim 30$ g cm$^{-2}$: below this, X-rays trigger enough magnetorotational turbulence midplane loft mm-cm sized particles high followed catastrophic fragmentation. A sharp gradient bounds depleted propagates outward 1$-2 over few Myr. Earth-mass planets migrate through similar timescale, whereas migration Jupiters limited supply gas. Gas-mediated must stall outside 0.04 AU, silicates are sublimated shifts much lower column. transition emerges dust/gas ratio MRI-active falls $X_d \sim 10^{-6}(a_d/\mu{\rm m})$, $a_d$ size.