The exoALMA Large Program observed 15 protoplanetary disks in high spectral resolution, unraveling their complex kinematic structures.

In Barraza-Alfaro et al. 2025, we predicted the kinematic signatures from large-scale turbulent motions in mock exoALMA observations of 12CO(J=3-2) emission of protoplanetary disks.

In our predictions, the large-scale turbulence driven by the vertical shear instability (VSI), the magnetorotational instability (MRI) and the gravitational instability (GI) are observable in exoALMA quality data. We found that the VSI is unlikely to be active in the exoALMA sample, while the MRI and GI could drive some of the observed spiral-like kinematic substructures. Disks with smooth kinematic structure within the exoALMA sample indicate that they are nearly laminar.

Marcelo Barraza-Alfaro et al 2025 ApJL 984 L21

 Observations have shown indirect evidence of a population of massive planets embedded in protoplanetary disks, whose interactions with the disk would substantially impact its structure.

In Barraza-Alfaro et al. 2024, we studied how a massive forming planet would affect the 3D gas velocity structure of a vertical shear instability-turbulent planet-forming disk,  focused on the observability of kinematic signatures.

We found that massive planets can damp the kinematic signatures of the vertical shear instability.

Barraza-Alfaro M., Flock M., Henning T., 2024, A&A, 683, A16

The vertical shear instability (VSI) is a hydrodynamical instability candidate to generate turbulence in protoplanetary disks.

In Barraza-Alfaro et al. 2021, we studied the feasibility of observing large-scale motions produced by the VSI in high-resolution ALMA observations of CO isotopologues. 

We found that ALMA has the capability to detect the corrugated velocity structure induced by the VSI. Observations of VSI kinematic signatures can reveal it as a source of turbulence in the outer regions of protoplanetary disks. 

Barraza-Alfaro M., Flock M., Marino S., Pérez S., 2021, A&A, 653, A113

Anticyclonic vortices have been proposed to create concentrations of millimeter sized dust particles, a starting point for planetesimal formation.

In Wölfer et al. 2025, we predicted the kinematic signatures of vortices, and compared with the observed non-Keplerian signatures in four exoALMA sources.

I contributed with 2D hydrodynamical simulations and mock ALMA observations.

Lisa Wölfer et al 2025 ApJL 984 L22

The vertical shear instability is a candidate mechanism to operate in the outer regions of protoplanetary disks driving turbulence.

A study of the convergence of the VSI is presented in Dang et al. 2024, finding a reduction of the radial wavelengths of the VSI corrugation modes with increasing the grid resolution of the numerical simulations.

I contributed with mock ALMA observations of the simulated VSI gas dynamics, concluding that the VSI may be only resolvable in the outermost regions of flared protoplanetary disks.

Dang Y., Cui C., Barraza-Alfaro M., 2024, MNRAS, 529, 918

Large-scale spiral arms have been observed in multi-wavelength observations of protoplanetary disks, yet their nature is still a puzzle. In Brown-Sevilla et al. 2021, I contributed with 2D hydrodynamical simulations exploring a scenario in which the spirals observed in the WaOph 6 disk are triggered by a massive planet. 

In order to create the observed spiral structure, a putative 10 Jupiter-mass planet located on the outskirts of the disk is needed. However, this scenario is in tension with current companion mass upper limits and mm-dust trapping theory.

Brown-Sevilla S.B., Keppler M., Barraza-Alfaro M., et al., 2021, A&A, 654, A35