Rapid Formation of Gas-giant Planets via Collisional Coagulation from Dust Grains to Planetary Cores

Gas-giant planets, such as Jupiter, Saturn and massive exoplanets, were formed via the gas accretion onto solid cores each with a mass of roughly ten Earth masses. However, rapid radial migration due to disk-planet interaction prevents formation planetesimal accretion. Comparably core growth pebble requires very protoplanetary disks because most pebbles fall into central star. Although formation, planetary migration, gas-giant have been studied much effort, full evolution path from dust planets are still uncertain. Here we report result simulations for collisional in whole disk. Dust realistic porosity allows icy planetesimals inner disk (> 10 au), while outer drift there grow planetesimals. The those suppresses their supplies small sustainably vicinity cores. This enables sufficiently within 0.2-0.4 million years, prior migration. Our models shows first giants form at 2-7 au rather common disks, agreement exoplanet solar systems.