2026A&A...705A..97K

Context. Dynamical disk-companion interactions can have a significant impact on the evolution of circumstellar disks, as these can produce perturbations to the material distribution, density, and temperature, affecting their potential for planet formation.
Aims. As part of the JWST GTO program MINDS, we analyze the mid-infrared (MIR) emission of three Class II binary systems: VW Cha, WX Cha, and RW Aur. Our aim is to investigate the impact of stellar multiplicity on the chemistry and physics of their inner disk.
Methods. We analyzed the 1D spectrum from JWST/MIRI-MRS for primary and secondary disks separately, extracted via a combination of forward modeling with a theoretical PSF and aperture photometry. Following the continuum subtraction, we modeled the molecular lines with 0D slab models. We interpreted the results by comparing our JWST spectra to VLT/CRIRES+, Spitzer/IRS. The extended MIR emission was compared to ALMA data, with the inclusion of the binary DF Tau in our sample.
Results. Primary and secondary disks are dramatically different in their MIR emission, with primary disks exhibiting H₂O-rich spectra and secondary disks being mostly line-poor with respect to the sensitivity of our spectra. When comparing MIRI-MRS to Spitzer/IRS, we observed a broad variability in the line emission of VW Cha A and in the continuum of RW Aur A. The disks around VW Cha BC and RW Aur B show evidence of ionizing radiation and a further comparison with ALMA at high angular resolution dust continuum suggests that the spectrum of RW Aur B is well explained by its ∼4 au cavity. All the systems show [Ne II] jet emission and three of them also show spatially resolved emission structures in H₂, likely originating from outflows and dynamical interactions.
Conclusions. Many of the observed features in the primary disks, such as enhanced water emission, could be linked to the increased accretion and radial drift produced by dynamical disk truncation. However, additional mechanisms are needed to explain the large differences between primary and secondary disks, potentially inner disk substructures. This work highlights the need for combining data from multiple facilities to fully understand the observations from JWST.