Presenter: Yuki TANAKA
Abstract:
Recently, pebble accretion attracts attention in theoretical works of planet formation. In this process, cm-sized particles, so-called pebbles, drift inward in the disk, and growth of planets will be accelerated due to accretion of pebbles onto protoplanets. Meanwhile, recent observations by ALMA have revealed that existence of clear gaps and rings in many very young disks. One explanation is that gas giants carve gaps in the dust disk and create such substructures, but it is unclear whether the planet with enough mass to create a gap can form in very young disks. Here we focus on much earlier stages, Class 0/I phases. Combining an analytical model of a disk around Class 0/I young stellar objects (YSOs) with a model of pebble accretion, we investigate possibility of giant planet formation in the early stages. We find that in many cases a time-scale of pebble accretion is much shorter compared to that in a typical protoplanetary disk. However, the accretion time-scale is not always a decreasing function of the gas accretion rate depending on parameters. We discuss a required initial mass of the protoplanets to form cores of the giant planets within Class 0/I phases.