exoALMA XXIII. Estimating Disk and Planet Properties from Dust Morphologies with DBNets2.0

TL;DR

This study uses simulation-based inference to estimate properties of embedded planets and disks from dust morphologies in 15 circumstellar disks, providing insights into planet migration and disk characteristics.

Contribution

The paper introduces DBNets2.0 for inferring planet and disk properties from dust structures, applying it to a large sample and comparing results with existing methods.

Findings

Good agreement with literature estimates.

Most inferred planets suggest inward migration.

Long viscous timescales challenge accretion models.

Abstract

The exoALMA large program provided an unprecedented view of the morphology and kinematics of 15 circumstellar disks, offering a biased but homogenous and well-characterized sample for population-level analysis. Continuum observations revealed numerous dust substructures, known to be potential signatures of embedded planets. We analyze the observed dust morphologies with the simulation-based inference tool DBNets2.0, assuming these are due to embedded planets at fixed locations, to infer the system properties. We estimate the putative planet mass, the disk $\alpha$-viscosity, scale-height, and dust Stokes number that would reproduce 19 substructures in 13 of the 15 exoALMA disks. We compare our results with literature estimates derived with different methods, and find good agreement in most cases. We further explore the implications of the inferred disk properties for accretion, showing that for the Herbig stars in our sample, the implied viscous accretion timescales are too long to account for their observed stellar accretion rates. Regarding planet migration, our results favor inward migration, with only three putative planets expected to migrate outward. Finally, we check for correlations of the inferred disk and planet properties with the disks' gas-to-dust mass ratio, non-axisymmetry index, and masses of the gas, dust, and host stars, finding no remarkable trend.