Exploring the formation of multiple dust-trapping rings in the inner Solar System

Context . 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 would be effective in blocking particles drifting from the outer to the inner disc. Yet this would not be enough to preserve dust in the inner disc. However, in low-viscosity discs and under specific conditions governing the gas cooling time, it has been shown that massive planets can also open secondary gaps, separated by density bumps, inwards of the main gap. The majority of studies of the process of secondary gap formation have been done in two dimensional equatorial simulations with prescribed disc cooling or by approximating the cooling from the disc photosphere. Recent results have shown that an appropriate computation of the disc cooling by including the treatment of radiation transport is key to determining the formation of secondary gaps. Aims . Our aim is to extend previous studies to three dimensional discs by also including radiative effects. Moreover, we also consider non-ideal magnetohydrodynamic effects in discs with a prescribed cooling time to explore the feedback of the magnetic field on secondary gap formation. Methods . We performed three dimensional hydrodynamical numerical simulations with a self-consistent treatment of radiative effects making use of a flux-limited diffusion approximation. We then extended our study to a similar disc including the magnetic field and non-ideal Ohmic and ambipolar effects. Results . We show that in the hydrodynamical model, a disc with low bulk viscosity ( α ν = 10 −4 ) and consistent treatment of radiative effects, a Jupiter-mass planet is capable of opening multiple gaps. We also show that multiple gaps and rings are formed by planetary masses close to the pebble isolation mass. In the presence of non-ideal MHD effects, multiple gaps and rings are also formed by a Jupiter-mass planet. Conclusions . A solid Jupiter core in low-viscosity discs blocks particles drifting towards and within the inner disc. The formation of multiple gaps and rings inside the planetary orbit at this stage is crucial to preserving dust reservoirs. Such reservoirs are pushed towards the inner part of the disc during Jupiter runaway growth and they are shown to be 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 when the disc is characterised by low viscosity.