Characterizing the Extended Molecular Hydrogen Winds in Protoplanetary Disks from the JWST Disk Infrared Spectroscopic Chemistry Survey

Abstract

We present a comprehensive analysis of extended H$_2$ emission from 34 protoplanetary disks observed with the JWST Disk Infrared Spectroscopic Chemistry Survey (JDISCS), supplemented by archival data. We investigated the morphology, kinematics, excitation conditions, and mass dynamics of H$_2$. Extended emission from pure rotational H$_2$ lines is found to be common, with 16 sources exhibiting clear signatures of disk winds. These include monopolar and bipolar structures in inclined disks and ring-like or bubble-like morphologies in face-on systems features indicative of wide-angle disk winds. Our analysis shows that the H$_2$ is consistent with slow {(4.2$^{+6.7}_{-3.0}$ km s$^{-1}$)} MHD driven winds. For ten disks, we model the wind morphology and find a median half-opening angle of $45\arcdeg^{+5}_{-4}$ and a characteristic power-law index of $\alpha \sim$ 1.6. Excitation analysis yields a median gas temperature of 624 $\pm$ 130 K and a column density of $\log(N_{\mathrm{tot}}\,[\mathrm{cm}^{-2}]) = 18.6 \pm 0.6$. The median wind mass-loss rate, ${\rm log_{10}}(\dot{\rm M}_{\rm wind}^{\rm tot}) = -9_{-0.4}^{+0.8}\,{\rm M_\odot\,yr^{-1}}$, implies that, if molecular winds are the dominant mechanism responsible for disk dispersal, a typical disk with a mass of $2-3\,M_{\rm Jup}$ would dissipate on a $\sim$2-3 Myr timescale, consistent with observed disk lifetimes. The $\dot{\rm M}_{\mathrm{\rm wind}}^{\rm tot}$ span a relatively narrow range ($\sim$2 dex) and do not correlate strongly with accretion rates onto the star, suggesting that the mass loss rate and the accretion rates are probing different timescales. Our findings demonstrate that spatially extended warm H$_2$ emission is a widespread and reliable tracer of molecular disk winds in protoplanetary systems.