JWST MIRI MRS Images Disk Winds, Water, and CO in an Edge-On Protoplanetary Disk

TL;DR

This study uses JWST MIRI MRS observations to analyze the spatial distribution of gas, dust, and PAHs in an edge-on protoplanetary disk, revealing outflows, scattering effects, and extended molecular emission.

Contribution

First detailed spatially resolved mid-IR imaging of an edge-on protoplanetary disk with JWST, revealing outflow structures, scattering phenomena, and extended PAH emission.

Findings

H$_2$ emission shows X-shaped structure consistent with MHD wind origin.

Detection of collimated bipolar jet in forbidden emission lines.

Extended H$_2$O, CO, and PAH emissions indicating scattering and outflow processes.

Abstract

We present JWST MIRI MRS observations of the edge-on protoplanetary disk around the young sub-solar mass star Tau 042021, acquired as part of the Cycle 1 GO program "Mapping Inclined Disk Astrochemical Signatures (MIDAS)." These data resolve the mid-IR spatial distributions of H$_2$, revealing X-shaped emission extending to ~200 au above the disk midplane with a semi-opening angle of $35 \pm 5$ degrees. We do not velocity-resolve the gas in the spectral images, but the measured semi-opening angle of the H$_2$ is consistent with an MHD wind origin. A collimated, bipolar jet is seen in forbidden emission lines from [Ne II], [Ne III], [Ni II], [Fe II], [Ar II], and [S III]. Extended H$_2$O and CO emission lines are also detected, reaching diameters between ~90 and 190 au, respectively. Hot molecular emission is not expected at such radii, and we interpret its extended spatial distribution as scattering of inner disk molecular emission by dust grains in the outer disk surface. H I recombination lines, characteristic of inner disk accretion shocks, are similarly extended, and are likely also scattered light from the innermost star-disk interface. Finally, we detect extended PAH emission at 11.3 microns co-spatial with the scattered light continuum, making this the first low-mass T Tauri star around which extended PAHs have been confirmed, to our knowledge. MIRI MRS line images of edge-on disks provide an unprecedented window into the outflow, accretion, and scattering processes within protoplanetary disks, allowing us to constrain the disk lifetimes and accretion and mass loss mechanisms.