A low accretion efficiency of planetesimals formed at planetary gap edges
Eriksson, Linn E. J. LU ; Ronnet, Thomas LU ; Johansen, Anders LU ; Helled, Ravit ; Valletta, Claudio and Petit, Antoine C. LU
(2022)
In Astronomy and Astrophysics
661.
- Abstract
Observations and models of giant planets indicate that such objects are enriched in heavy elements compared to solar abundances. The prevailing view is that giant planets accreted multiple Earth masses of heavy elements after the end of core formation. Such late solid enrichment is commonly explained by the accretion of planetesimals. Planetesimals are expected to form at the edges of planetary gaps, and here we address the question of whether these planetesimals can be accreted in large enough amounts to explain the inferred high heavy element contents of giant planets. We performed a series of N-body simulations of the dynamics of planetesimals and planets during the planetary growth phase, taking gas drag into account as well... (More)
Observations and models of giant planets indicate that such objects are enriched in heavy elements compared to solar abundances. The prevailing view is that giant planets accreted multiple Earth masses of heavy elements after the end of core formation. Such late solid enrichment is commonly explained by the accretion of planetesimals. Planetesimals are expected to form at the edges of planetary gaps, and here we address the question of whether these planetesimals can be accreted in large enough amounts to explain the inferred high heavy element contents of giant planets. We performed a series of N-body simulations of the dynamics of planetesimals and planets during the planetary growth phase, taking gas drag into account as well as the enhanced collision cross section caused by the extended envelopes. We considered the growth of Jupiter and Saturn via gas accretion after reaching the pebble isolation mass and we included their migration in an evolving disk. We find that the accretion efficiency of planetesimals formed at planetary gap edges is very low: less than 10% of the formed planetesimals are accreted even in the most favorable cases, which in our model corresponds to a few Earth masses. When planetesimals are assumed to form beyond the feeding zone of the planets, extending to a few Hill radii from a planet, accretion becomes negligible. Furthermore, we find that the accretion efficiency increases when the planetary migration distance is increased and that the efficiency does not increase when the planetesimal radii are decreased. Based on these results, we conclude that it is difficult to explain the large heavy element content of giant planets with planetesimal accretion during the gas accretion phase. Alternative processes most likely are required, such as accretion of vapor deposited by drifting pebbles.
(Less)
- author
- Eriksson, Linn E. J.
LU
; Ronnet, Thomas
LU
; Johansen, Anders
LU
; Helled, Ravit
; Valletta, Claudio
and Petit, Antoine C.
LU
- organization
- publishing date
- 2022-05-01
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- Planet-disk interactions, Planets and satellites: formation, Protoplanetary disks
- in
- Astronomy and Astrophysics
- volume
- 661
- article number
- A73
- pages
- 13 pages
- publisher
- EDP Sciences
- external identifiers
-
- scopus:85130368374
- ISSN
- 0004-6361
- DOI
- 10.48550/arXiv.2202.12723
- language
- English
- LU publication?
- yes
- additional info
- Publisher Copyright: ©
- id
- b1c282cd-5f1d-4a5f-9473-1154da886b35
- date added to LUP
- 2022-07-21 10:09:04
- date last changed
- 2024-04-18 08:28:36
@article{b1c282cd-5f1d-4a5f-9473-1154da886b35,
abstract = {{<p>Observations and models of giant planets indicate that such objects are enriched in heavy elements compared to solar abundances. The prevailing view is that giant planets accreted multiple Earth masses of heavy elements after the end of core formation. Such late solid enrichment is commonly explained by the accretion of planetesimals. Planetesimals are expected to form at the edges of planetary gaps, and here we address the question of whether these planetesimals can be accreted in large enough amounts to explain the inferred high heavy element contents of giant planets. We performed a series of <i>N</i>-body simulations of the dynamics of planetesimals and planets during the planetary growth phase, taking gas drag into account as well as the enhanced collision cross section caused by the extended envelopes. We considered the growth of Jupiter and Saturn via gas accretion after reaching the pebble isolation mass and we included their migration in an evolving disk. We find that the accretion efficiency of planetesimals formed at planetary gap edges is very low: less than 10% of the formed planetesimals are accreted even in the most favorable cases, which in our model corresponds to a few Earth masses. When planetesimals are assumed to form beyond the feeding zone of the planets, extending to a few Hill radii from a planet, accretion becomes negligible. Furthermore, we find that the accretion efficiency increases when the planetary migration distance is increased and that the efficiency does not increase when the planetesimal radii are decreased. Based on these results, we conclude that it is difficult to explain the large heavy element content of giant planets with planetesimal accretion during the gas accretion phase. Alternative processes most likely are required, such as accretion of vapor deposited by drifting pebbles.</p>}},
author = {{Eriksson, Linn E. J. and Ronnet, Thomas and Johansen, Anders and Helled, Ravit and Valletta, Claudio and Petit, Antoine C.}},
issn = {{0004-6361}},
keywords = {{Planet-disk interactions; Planets and satellites: formation; Protoplanetary disks}},
language = {{eng}},
month = {{05}},
publisher = {{EDP Sciences}},
series = {{Astronomy and Astrophysics}},
title = {{A low accretion efficiency of planetesimals formed at planetary gap edges}},
url = {{http://dx.doi.org/10.48550/arXiv.2202.12723}},
doi = {{10.48550/arXiv.2202.12723}},
volume = {{661}},
year = {{2022}},
}