Disk And Atmosphere Composition Of Multi-Planet Systems
In protoplanetary disks, small mm-cm-sized pebbles drift inwards which can aid planetary growth and influence the chemical composition of their natal disks. Gaps in protoplanetary disks can hinder the effective inward transport of pebbles by trapping the material in pressure bumps. Here we explore how multiple planets change the vapour enrichment by gap opening.
For this, we extend the chemcomp code to include multiple growing planets and investigate the effect of 1, 2 & 3 planets on the water content and C/O ratio in the gas disk as well as the final composition of the planetary atmosphere. We follow planet migration over evaporation fronts and find that previously trapped pebbles evaporate relatively quickly and enrich the gas.
We also find that in a multi-planet system, the atmosphere composition can be reduced in carbon and oxygen compared to the case without other planets, due to the blocking of volatile-rich pebbles by an outer planet. This effect is stronger for lower viscosities because planets migrate further at higher viscosities and eventually cross inner evaporation fronts, releasing the previously trapped pebbles.
Interestingly, we find that nitrogen remains super-stellar regardless of the number of planets in the system such that super-stellar values in N/H of giant planet atmospheres may be a tracer for the importance of pebble drift and evaporation.
Water fraction in the gas surface density normalised to the initial fraction for α = 1, 5, & 10 × 10−4 from top to bottom. The black lines represent the migration paths of planets. The grey area shades the region exterior to the water ice line. Note, only some plots show the path of planets because depending on the setup either no planets are present or they remain outside of 2 AU. — astro-ph.EP
Mark Eberlein, Bertram Bitsch, Ravit Helled
Comments: 17 pages, 9 figures, 5 tables, accepted by A&A
Subjects: Earth and Planetary Astrophysics (astro-ph.EP)
Cite as: arXiv:2407.20117 [astro-ph.EP] (or arXiv:2407.20117v1 [astro-ph.EP] for this version)
Submission history
From: Mark Eberlein
[v1] Mon, 29 Jul 2024 15:50:10 UTC (1,262 KB)
https://arxiv.org/abs/2407.20117
Astrobiology,