IPA: Morphology and Kinematics of Molecular Hydrogen Winds in Five Young Protostars across the Mass Spectrum Observed with JWST

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Molecular winds may play a key role in governing angular momentum transport and accretion during the early evolution of protostars. We present the morphology and kinematic properties of the H 2 emission in five young, envelope-dominated protostars across a broad bolometric luminosity range, from 0.2 to 10 4 L ⊙ , observed with the NIRSpec/integral field unit and MIRI/Medium Resolution Spectrograph on board JWST as part of the Investigating Protostellar Accretion (IPA) program. A rich set of pure rotational lines of H 2 , up to v = 0–0 S (18), and a few rovibrational lines are detected in the winds, revealing bipolar structures. The H 2 lines show a stratified/onion-like structure morphologically and kinematically, where the lines with higher E u / k show a higher degree of collimation and higher velocities. Additionally, the wind velocity scales with the L bol of the host protostellar system. In four out of five protostars, H 2 emission fills the outflow cavity without showing pronounced limb brightening. We also report a tentative detection of H 2 wind rotation in IRAS 16253, which suggests a launch radius of ∼4 au and a magnetic lever arm parameter of ∼5–10. Taken together, these properties of the H 2 winds can be explained by the magnetohydrodynamic disk wind models. We detect a collimated, high-velocity H 2 jet toward HOPS 370, which is more evolved than the extremely young source HH 211 but is accreting at a high accretion rate. This suggests that the presence of collimated molecular jets in protostars is more closely connected to accretion rate than system age.