Forming giant planets around late-M dwarfs : Pebble accretion and planet-planet collision
(2024) In Astronomy and Astrophysics 682.- Abstract
We propose a pebble-driven core accretion scenario to explain the formation of giant planets around the late-M dwarfs of M∗=0.1-0.2 M⊙. In order to explore the optimal disk conditions for giant planet, we performed N-body simulations to investigate the growth and dynamical evolution of both single and multiple protoplanets in the disks with both inner viscously heated and outer stellar irradiated regions. The initial masses of the protoplanets are either assumed to be equal to 0.01 M⊕ or calculated based on the formula derived from streaming instability simulations. Our findings indicate that massive planets are more likely to form in disks with longer lifetimes, higher solid masses, moderate to high levels of disk turbulence, and... (More)
We propose a pebble-driven core accretion scenario to explain the formation of giant planets around the late-M dwarfs of M∗=0.1-0.2 M⊙. In order to explore the optimal disk conditions for giant planet, we performed N-body simulations to investigate the growth and dynamical evolution of both single and multiple protoplanets in the disks with both inner viscously heated and outer stellar irradiated regions. The initial masses of the protoplanets are either assumed to be equal to 0.01 M⊕ or calculated based on the formula derived from streaming instability simulations. Our findings indicate that massive planets are more likely to form in disks with longer lifetimes, higher solid masses, moderate to high levels of disk turbulence, and larger initial masses of protoplanets. In the single protoplanet growth cases, the highest planet core mass that can be reached is generally lower than the threshold necessary to trigger rapid gas accretion, which impedes the formation of giant planets. Nonetheless, in multi-protoplanet cases, the cores can exceed the pebble isolation mass barrier aided by frequent planet-planet collisions. This consequently speeds their gas accretion up and promotes giant planet formation, making the optimal parameter space to grow giant planets substantially wider. Taken together, our results suggest that even around very-low-mass stellar hosts, the giant planets with orbital periods of ≤100 days are still likely to form when lunar-mass protoplanets first emerge from planetesimal accretion and then grow rapidly by a combination of pebble accretion and planet-planet collisions in disks with a high supply of a pebble reservoir >50 M⊕ and a turbulent level of αt ~ 10-3-10-2.
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- author
- Pan, Mengrui ; Liu, Beibei ; Johansen, Anders LU ; Ogihara, Masahiro ; Wang, Su ; Ji, Jianghui ; Wang, Sharon X. ; Feng, Fabo and Ribas, Ignasi
- organization
- publishing date
- 2024-02-01
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- methods: numerical, planets and satellites: dynamical evolution and stability, planets and satellites: formation, planets and satellites: gaseous planets
- in
- Astronomy and Astrophysics
- volume
- 682
- article number
- A89
- publisher
- EDP Sciences
- external identifiers
-
- scopus:85184952111
- ISSN
- 0004-6361
- DOI
- 10.1051/0004-6361/202347664
- language
- English
- LU publication?
- yes
- id
- 89b3e5bb-10ee-4dc5-9c71-83878942a854
- date added to LUP
- 2024-02-22 14:04:30
- date last changed
- 2024-02-22 14:04:30
@article{89b3e5bb-10ee-4dc5-9c71-83878942a854,
abstract = {{<p>We propose a pebble-driven core accretion scenario to explain the formation of giant planets around the late-M dwarfs of M∗=0.1-0.2 M⊙. In order to explore the optimal disk conditions for giant planet, we performed N-body simulations to investigate the growth and dynamical evolution of both single and multiple protoplanets in the disks with both inner viscously heated and outer stellar irradiated regions. The initial masses of the protoplanets are either assumed to be equal to 0.01 M⊕ or calculated based on the formula derived from streaming instability simulations. Our findings indicate that massive planets are more likely to form in disks with longer lifetimes, higher solid masses, moderate to high levels of disk turbulence, and larger initial masses of protoplanets. In the single protoplanet growth cases, the highest planet core mass that can be reached is generally lower than the threshold necessary to trigger rapid gas accretion, which impedes the formation of giant planets. Nonetheless, in multi-protoplanet cases, the cores can exceed the pebble isolation mass barrier aided by frequent planet-planet collisions. This consequently speeds their gas accretion up and promotes giant planet formation, making the optimal parameter space to grow giant planets substantially wider. Taken together, our results suggest that even around very-low-mass stellar hosts, the giant planets with orbital periods of ≤100 days are still likely to form when lunar-mass protoplanets first emerge from planetesimal accretion and then grow rapidly by a combination of pebble accretion and planet-planet collisions in disks with a high supply of a pebble reservoir >50 M⊕ and a turbulent level of αt ~ 10-3-10-2.</p>}},
author = {{Pan, Mengrui and Liu, Beibei and Johansen, Anders and Ogihara, Masahiro and Wang, Su and Ji, Jianghui and Wang, Sharon X. and Feng, Fabo and Ribas, Ignasi}},
issn = {{0004-6361}},
keywords = {{methods: numerical; planets and satellites: dynamical evolution and stability; planets and satellites: formation; planets and satellites: gaseous planets}},
language = {{eng}},
month = {{02}},
publisher = {{EDP Sciences}},
series = {{Astronomy and Astrophysics}},
title = {{Forming giant planets around late-M dwarfs : Pebble accretion and planet-planet collision}},
url = {{http://dx.doi.org/10.1051/0004-6361/202347664}},
doi = {{10.1051/0004-6361/202347664}},
volume = {{682}},
year = {{2024}},
}