Combined Effects of Disk Winds and Turbulence-Driven Accretion on Planet Populations

TL;DR

This study models how combined disk winds and turbulence-driven accretion influence planet formation, revealing that a distribution of disk properties better matches observed exoplanet populations, including super Earths and hot Jupiters.

Contribution

It introduces a comprehensive model incorporating both disk winds and turbulence effects, improving the match between simulated and observed exoplanet distributions.

Findings

Distributions with variable turbulence and wind strengths fit observations better.

Models produce a significant super Earth population at 0.03-2 AU.

Good agreement with observed exoplanet mass-radius distribution after atmospheric effects.

Abstract

Recent surveys show that protoplanetary disks have lower levels of turbulence than expected based on their observed accretion rates. A viable solution to this is that magnetized disk winds dominate angular momentum transport. This has several important implications for planet formation processes. We compute the physical and chemical evolution of disks and the formation and migration of planets under the combined effects of angular momentum transport by turbulent viscosity and disk winds. We take into account the critical role of planet traps to limit Type I migration in all of these models and compute thousands of planet evolution tracks for single planets drawn from a distribution of initial disk properties and turbulence strengths. We do not consider multi-planet models nor include N-body planet-planet interactions. Within this physical framework we find that populations with a constant value disk turbulence and winds strength produce mass-semimajor axis distributions in the M-a diagram with insufficient scatter to compare reasonably with observations. However, populations produced as a consequence of sampling disks with a distribution of the relative strengths of disk turbulence and winds fit much better. Such models give rise to a substantial super Earth population at orbital radii 0.03-2 AU, as well as a clear separation between the produced hot Jupiter and warm Jupiter populations. Additionally, this model results in a good comparison with the exoplanetary mass-radius distribution in the M-R diagram after post-disk atmospheric photoevaporation is accounted for.