Planet formation throughout the Milky Way : Planet populations in the context of Galactic chemical evolution
(2023) In Astronomy and Astrophysics 678.- Abstract
As stellar compositions evolve over time in the Milky Way, so will the resulting planet populations. In order to place planet formation in the context of Galactic chemical evolution, we made use of a large (N = 5325) stellar sample representing the thin and thick discs, defined chemically, and the halo, and we simulated planet formation by pebble accretion around these stars. We built a chemical model of their protoplanetary discs, taking into account the relevant chemical transitions between vapour and refractory minerals, in order to track the resulting compositions of formed planets. We find that the masses of our synthetic planets increase on average with increasing stellar metallicity [Fe/H] and that giant planets and super-Earths... (More)
As stellar compositions evolve over time in the Milky Way, so will the resulting planet populations. In order to place planet formation in the context of Galactic chemical evolution, we made use of a large (N = 5325) stellar sample representing the thin and thick discs, defined chemically, and the halo, and we simulated planet formation by pebble accretion around these stars. We built a chemical model of their protoplanetary discs, taking into account the relevant chemical transitions between vapour and refractory minerals, in order to track the resulting compositions of formed planets. We find that the masses of our synthetic planets increase on average with increasing stellar metallicity [Fe/H] and that giant planets and super-Earths are most common around thin-disc (α-poor) stars since these stars have an overall higher budget of solid particles. Giant planets are found to be very rare (≲1%) around thick-disc (α-rich) stars and nearly non-existent around halo stars. This indicates that the planet population is more diverse for more metal-rich stars in the thin disc. Water-rich planets are less common around low-metallicity stars since their low metallicity prohibits efficient growth beyond the water ice line. If we allow water to oxidise iron in the protoplanetary disc, this results in decreasing core mass fractions with increasing [Fe/H]. Excluding iron oxidation from our condensation model instead results in higher core mass fractions, in better agreement with the core-mass fraction of Earth, that increase with increasing [Fe/H]. Our work demonstrates how the Galactic chemical evolution and stellar parameters, such as stellar mass and chemical composition, can shape the resulting planet population.
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- author
- Nielsen, Jesper ; Gent, Matthew Raymond ; Bergemann, Maria ; Eitner, Philipp and Johansen, Anders LU
- organization
- publishing date
- 2023-10-01
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- Planets and satellites: composition, Planets and satellites: formation, Stars: abundances
- in
- Astronomy and Astrophysics
- volume
- 678
- article number
- A74
- publisher
- EDP Sciences
- external identifiers
-
- scopus:85175021349
- ISSN
- 0004-6361
- DOI
- 10.1051/0004-6361/202346697
- language
- English
- LU publication?
- yes
- id
- 53cea0f1-2c4f-4ad3-906c-c4d88a136c64
- date added to LUP
- 2024-01-12 08:53:40
- date last changed
- 2025-04-04 15:13:20
@article{53cea0f1-2c4f-4ad3-906c-c4d88a136c64,
abstract = {{<p>As stellar compositions evolve over time in the Milky Way, so will the resulting planet populations. In order to place planet formation in the context of Galactic chemical evolution, we made use of a large (N = 5325) stellar sample representing the thin and thick discs, defined chemically, and the halo, and we simulated planet formation by pebble accretion around these stars. We built a chemical model of their protoplanetary discs, taking into account the relevant chemical transitions between vapour and refractory minerals, in order to track the resulting compositions of formed planets. We find that the masses of our synthetic planets increase on average with increasing stellar metallicity [Fe/H] and that giant planets and super-Earths are most common around thin-disc (α-poor) stars since these stars have an overall higher budget of solid particles. Giant planets are found to be very rare (≲1%) around thick-disc (α-rich) stars and nearly non-existent around halo stars. This indicates that the planet population is more diverse for more metal-rich stars in the thin disc. Water-rich planets are less common around low-metallicity stars since their low metallicity prohibits efficient growth beyond the water ice line. If we allow water to oxidise iron in the protoplanetary disc, this results in decreasing core mass fractions with increasing [Fe/H]. Excluding iron oxidation from our condensation model instead results in higher core mass fractions, in better agreement with the core-mass fraction of Earth, that increase with increasing [Fe/H]. Our work demonstrates how the Galactic chemical evolution and stellar parameters, such as stellar mass and chemical composition, can shape the resulting planet population.</p>}},
author = {{Nielsen, Jesper and Gent, Matthew Raymond and Bergemann, Maria and Eitner, Philipp and Johansen, Anders}},
issn = {{0004-6361}},
keywords = {{Planets and satellites: composition; Planets and satellites: formation; Stars: abundances}},
language = {{eng}},
month = {{10}},
publisher = {{EDP Sciences}},
series = {{Astronomy and Astrophysics}},
title = {{Planet formation throughout the Milky Way : Planet populations in the context of Galactic chemical evolution}},
url = {{http://dx.doi.org/10.1051/0004-6361/202346697}},
doi = {{10.1051/0004-6361/202346697}},
volume = {{678}},
year = {{2023}},
}