According to both spectroscopic measurements and interior models, Jupiter,
Saturn, Uranus and Neptune possess gaseous envelopes that are enriched in
heavy elements compared to the Sun. Straightforward application of the
dominant theories of gas giant formation - core accretion and gravitational
instability - fail to provide the observed enrichment, suggesting that the
surplus heavy elements were somehow dumped onto the planets after the
envelopes were already in existence.
Previous work has shown that if giant planets rapidly reached their cur
rent configuration and radii, they do not accrete the remaining planetesimals
efficiently enough to explain their observed heavy-element surplus. We ex
plore the likely scenario that the effective accretion cross-sections of the
giants were enhanced by the presence of the massive circumplanetary disks
out of which their regular satellite systems formed. Perhaps surprisingly,
we find that a simple model with protosatellite disks around Jupiter and
Saturn can meet known constraints without tuning any parameters. Fur
thermore, we show that the heavy-element budgets in Jupiter and Saturn
can be matched slightly better if Saturn’s envelope (and disk) are formed
roughly 0.1 — 10 Myr after that of Jupiter.
We also show that giant planets forming in an initially-compact con
figuration can acquire the observed enrichments if they are surrounded by
similar protosatellite disks.
Protosatellite disks efficiently increase the capture cross-section, and thus
the metallicity, of the giant planets. Detailed models of planet formation
must therefore account for the presence of such disks during the early stages
of solar system formation. / Science, Faculty of / Physics and Astronomy, Department of / Graduate
| Identifer | oai:union.ndltd.org:UBC/oai:circle.library.ubc.ca:2429/4066 |
| Date | 11 1900 |
| Creators | Coffey, Jaime Lee |
| Publisher | University of British Columbia |
| Source Sets | University of British Columbia |
| Language | English |
| Detected Language | English |
| Type | Text, Thesis/Dissertation |
| Format | 922632 bytes, application/pdf |
| Rights | Attribution-NonCommercial-NoDerivatives 4.0 International, http://creativecommons.org/licenses/by-nc-nd/4.0/ |
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