Promoted Mass Growth of Multiple, Distant Giant Planets through Pebble Accretion and Planet-Planet Collision. (arXiv:2006.06451v1 [astro-ph.EP])
<a href="http://arxiv.org/find/astro-ph/1/au:+Wimarsson_J/0/1/0/all/0/1">John Wimarsson</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Liu_B/0/1/0/all/0/1">Beibei Liu</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ogihara_M/0/1/0/all/0/1">Masahiro Ogihara</a>
We propose a pebble-driven planet formation scenario to form giant planets
with high multiplicity and large orbital distances in the early gas disk phase.
We perform N-body simulations to investigate the growth and migration of
low-mass protoplanets in the disk with inner viscously heated and outer stellar
irradiated regions. The key feature of this model is that the giant planet
cores grow rapidly by a combination of pebble accretion and planet-planet
collisions. This consequently speeds up their gas accretion. Because of
efficient growth, the planet transitions from rapid type I migration to slow
type II migration early, reducing the inward migration substantially. Multiple
giant planets can sequentially form in this way with increasing semimajor axes.
Both mass growth and orbital retention are more pronounced when a large number
of protoplanets are taken into account compared to the case of single planet
growth. Eventually, a few numbers of giant planets form with orbital distances
of a few to a few tens of AUs within $1.5{-}3$ Myr after the birth of the
protoplanets. The resulting simulated planet populations could be linked to the
substructures exhibited in disk observations as well as large orbital distance
exoplanets observed in radial velocity and microlensing surveys.
We propose a pebble-driven planet formation scenario to form giant planets
with high multiplicity and large orbital distances in the early gas disk phase.
We perform N-body simulations to investigate the growth and migration of
low-mass protoplanets in the disk with inner viscously heated and outer stellar
irradiated regions. The key feature of this model is that the giant planet
cores grow rapidly by a combination of pebble accretion and planet-planet
collisions. This consequently speeds up their gas accretion. Because of
efficient growth, the planet transitions from rapid type I migration to slow
type II migration early, reducing the inward migration substantially. Multiple
giant planets can sequentially form in this way with increasing semimajor axes.
Both mass growth and orbital retention are more pronounced when a large number
of protoplanets are taken into account compared to the case of single planet
growth. Eventually, a few numbers of giant planets form with orbital distances
of a few to a few tens of AUs within $1.5{-}3$ Myr after the birth of the
protoplanets. The resulting simulated planet populations could be linked to the
substructures exhibited in disk observations as well as large orbital distance
exoplanets observed in radial velocity and microlensing surveys.
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