From spirals to rings: dust dynamics in gravitoturbulent protoplanetary discs after late infall
Abstract
Substructures appear to be a common trait of all extended protoplanetary discs. They are found notably in discs still surrounded by ambient, possibly infalling material. In this study, we revisit the observational signatures of gravitational instability (GI) in the dust and gas emission of protoplanetary discs. We focus on discs undergoing a short-lived episode of late infall that triggers spirals via GI, in order to investigate the long-term dynamics of millimetre-sized dust. We performed 2D hydrodynamical simulations modelling gas and millimetre-sized dust in a self-gravitating disc, with a simplified treatment of stellar irradiation and infall. Results were post-processed by 3D radiative transfer calculations. During infall, GI sets in and the disc develops a gravitoturbulent state characterised by the continuous formation of spirals. Shortly after infall ends, the millimetre-sized dust remains well coupled to the gas, and the dust emission exhibits large-scale spirals in both near-infrared scattered light and continuum emission. Even long after infall has ceased, two-armed spirals are persistently excited by GI in specific regions of the disc. Their dissipation entails the formation of multiple long-lasting pressure maxima, which can be viewed as vestiges of shocks induced by the spirals. They form persistent dust rings that are more or less axisymmetrical. Consequently, once late infall ends, a massive disc can gradually evolve from a disc with spirals in the continuum into one featuring multiple, potentially lopsided bright rings in the continuum. In near-infrared scattered light, the disc initially displays multiple spirals during infall or shortly after it ceases, before ultimately exhibiting multiple rings. The persistent excitation of spirals implies, however, that the residual line-of-sight velocity, derived from line emission, shows large-scale spirals across the disc.
Related
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BibTeX
@misc{baruteau2026from,
title = {{From spirals to rings: dust dynamics in gravitoturbulent protoplanetary discs after late infall}},
author = {Clément Baruteau and Steven Rendon Restrepo and Gaylor Wafflard-Fernandez and Sebastián Pérez and Zhaohuan Zhu and Hans Baehr and Farzana Meru and Jean-François Gonzalez and Sergei Nayakshin and Sahl Rowther},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.10375},
eprint = {2609.10375},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.10375},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - From spirals to rings: dust dynamics in gravitoturbulent protoplanetary discs after late infall
AU - Clément Baruteau
AU - Steven Rendon Restrepo
AU - Gaylor Wafflard-Fernandez
AU - Sebastián Pérez
AU - Zhaohuan Zhu
AU - Hans Baehr
AU - Farzana Meru
AU - Jean-François Gonzalez
AU - Sergei Nayakshin
AU - Sahl Rowther
PY - 2026
DA - 2026/09/09
PB - arXiv
DO - 10.48550/arxiv.2609.10375
UR - https://arxiv.org/abs/2609.10375
AB - Substructures appear to be a common trait of all extended protoplanetary discs. They are found notably in discs still surrounded by ambient, possibly infalling material. In this study, we revisit the observational signatures of gravitational instability (GI) in the dust and gas emission of protoplanetary discs. We focus on discs undergoing a short-lived episode of late infall that triggers spirals via GI, in order to investigate the long-term dynamics of millimetre-sized dust. We performed 2D hydrodynamical simulations modelling gas and millimetre-sized dust in a self-gravitating disc, with a simplified treatment of stellar irradiation and infall. Results were post-processed by 3D radiative transfer calculations. During infall, GI sets in and the disc develops a gravitoturbulent state characterised by the continuous formation of spirals. Shortly after infall ends, the millimetre-sized dust remains well coupled to the gas, and the dust emission exhibits large-scale spirals in both near-infrared scattered light and continuum emission. Even long after infall has ceased, two-armed spirals are persistently excited by GI in specific regions of the disc. Their dissipation entails the formation of multiple long-lasting pressure maxima, which can be viewed as vestiges of shocks induced by the spirals. They form persistent dust rings that are more or less axisymmetrical. Consequently, once late infall ends, a massive disc can gradually evolve from a disc with spirals in the continuum into one featuring multiple, potentially lopsided bright rings in the continuum. In near-infrared scattered light, the disc initially displays multiple spirals during infall or shortly after it ceases, before ultimately exhibiting multiple rings. The persistent excitation of spirals implies, however, that the residual line-of-sight velocity, derived from line emission, shows large-scale spirals across the disc.
ER -