On the formation of multiple dust-trapping rings in the inner Solar system

TL;DR

The paper investigates whether Jupiter can form multiple dust-trapping rings inside its orbit by generating secondary gaps in a three-dimensional protoplanetary disk. Using self-consistent radiative transfer via Flux Limited Diffusion and, in separate runs, non-ideal MHD (Ohmic and ambipolar diffusion) in low-viscosity disks, the authors show that Jupiter-analog masses, and masses near the pebble isolation threshold, can produce multiple inner gaps and pressure bumps that trap dust. The results persist across fully radiative and MHD regimes, indicating robust pathways to create sustained inner dust reservoirs compatible with isotopic evidence from meteorites. This mechanism links planetary growth, disk thermodynamics, and magnetic diffusion to a plausible early Solar System dust evolution, potentially explaining why inner-disk dust persisted over Myr timescales and how multiple trapping sites could have formed and merged as Jupiter grew.

Abstract

Isotopic properties of meteorites provide evidence that multiple dust trap or pressure bumps had to form and persist in the inner Solar System on a timescale of millions of years. The formation of a pressure bump at the outer edge of the gap opened by Jupiter blocks particles drifting from the outer to the inner disk. This is not enough to preserve dust in the inner disk. However, in low viscosity disks, under specific condition on the gas cooling time, massive planets can also open secondary gaps, separated by density bumps, inward of the main gap. The majority of studies have been done in two dimensional equatorial simulations with prescribed disk cooling. Recent results have shown that including the treatment of radiation transport is key to determine the formation of secondary gaps. We extend previous studies to three dimensional disks including radiative effects and we also consider non ideal MHD effects, in disks with prescribed cooling time. We perform three dimensional hydrodynamical numerical simulations with self consistent treatment of radiative effects and including the magnetic field with non ideal Ohmic and Ambipolar effects. We show that in a disk with low bulk viscosity and consistent treatment of radiative effects, planetary masses close to the pebble isolation mass as well as a Jupiter massive planet open multiple gaps. In the presence of non ideal MHD effects multiple gaps and rings are also formed by a Jupiter massive planet.In conclusion the formation of multiple gaps and rings inside the planetary orbit is crucial to preserve dust reservoirs. Such reservoirs are pushed towards the inner part of the disk during Jupiter runaway growth and are persistent after Jupiter's growth. Multiple dust reservoirs could therefore be present in the inner Solar System since the formation of Jupiter's solid core if the disk had low-viscosity.

Figures (15)

• Figure 1: Simulation HD$_{Bae}$. Two dimensional distribution in the $(r,\varphi)$ plane of the midplane density $\rho$ normalized over the azimuthally averaged value $<\rho>$ at $t=10$ orbits when the planet has just reached a Jovian mass. In order to compare to Fig.6 of Bae2016 the y-axis is plotted using a logarithmic scale.
• Figure 2: Top panel: azimuthally averaged surface density profile for simulation HD$_{Bae}$ . Bottom panel azimuthally averaged $\eta$ parameter. The planet is kept on a fixed circular orbit at $r/r_p=1$ and the ticks on the $x$-axis (as well as the vertical black lines) indicate the values of $\eta \sim 0$ with positive slope. The horizontal black line corresponds to $\eta =0$. The damping region extends radially from $r_{min}/r_0$ to the dot dashed line.
• Figure 3: Perturbed surface density of the HD$_{Bae}$ simulation at the same snapshots represented in Fig.\ref{['Fig:BaeEta']}. The dashed lines indicate the radial position of the pressure bumps, i.e. the values of r for which $\eta=0$ in Fig.\ref{['Fig:BaeEta']}. The dot-dashed line indicates the boundary of the damping region.
• Figure 4: Disk cooling time, density and opacity in the $(R,Z)\equiv (r\sin(\theta),r\cos(\theta))$ plane of the disk in thermal equilibrium before the insertion of the planet.
• Figure 5: Same as Fig.\ref{['Fig:tau0']} for azimuthally averaged quantities for the three dimensional simulation HD$_{rad}$J with embedded a Jupiter mass planet. The snapshot corresponds to the end of the integration at 150 orbital periods at the planet location ($5.2 au$).