Rapid formation of Gas Giant Planets via Collisional Coagulation from\u00a0Dust Grains to Planetary Cores<\/p>\n\n\n\n
speaker: Hiroshi Kobayashi<\/p>\n\n\n\n
Abstract:<\/p>\n\n\n\n
Gas-giant planets, such as Jupiter, Saturn and massive exoplanets, were formed via the gas\u00a0accretion onto the solid cores each with a mass of roughly ten Earth masses. However, rapid\u00a0radial migration due to disk-planet interaction prevents the formation of such massive cores via\u00a0planetesimal accretion. Comparably rapid core growth via pebble accretion requires very\u00a0massive protoplanetary disks because most pebbles fall into the central star. Although\u00a0planetesimal formation, planetary migration, and gas-giant core formation have been studied\u00a0with much effort, the full evolution path from dust to planets are still uncertain. Here we report\u00a0the result of full simulations for collisional evolution from dust to planets in a whole disk. Dust\u00a0growth with realistic porosity allows the formation of icy planetesimals in the inner disk (> 10\u00a0au), while pebbles formed in the outer disk drift to the inner disk and there grow to\u00a0planetesimals. The growth of those pebbles to planetesimals suppresses their radial drift and\u00a0supplies small planetesimals sustainably in the vicinity of cores. This enables rapid formation of\u00a0sufficiently massive planetary cores within 0.2-0.4 million years, prior to the planetary\u00a0migration. Our models shows first gas giants form at 2-7 au in rather common protoplanetary\u00a0disks, in agreement with the exoplanet and solar systems.<\/p>\n","protected":false},"excerpt":{"rendered":"