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

Himanshu Tyagi; P. Manoj; Mayank Narang; S. Thomas Megeath; Robert Gutermuth; Lee Hartmann; Alessio Caratti o Garatti; Dan M. Watson; David A. Neufeld; Ewine F. Van Dishoeck; Neal J. Evans II; Vinod Chandra Pathak; Samuel A. Federman; Tyler L. Bourke; Yao-Lun Yang; Guillem Anglada; Henrik Beuther; Leslie W. Looney; Rolf Kuiper; Pamela Klaassen; Pooneh Nazari; Bihan Banerjee; Joel Green; Sujay Vijay Jadhav; Mayra Osorio; B. Shridharan; Amelia M. Stutz; Thomas Stanke; John J. Tobin; Lukasz Tychoniec; Scott Wolk; Manya Arora

arXiv · 2608.09920

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

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Abstract

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 $10^4~L_{\odot}$, observed with the NIRSpec/IFU and MIRI/MRS onboard 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 ro-vibrational 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 $E_{\rm up}$ show a higher degree of collimation and higher velocities. Additionally, the wind velocity scales with the $L_{\rm bol}$ of the host protostellar system. In 4 out of 5 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 $\sim4$ au and the magnetic lever arm parameter of $\sim5-10$. 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.

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Himanshu Tyagi, P. Manoj, Mayank Narang, S. Thomas Megeath, Robert Gutermuth, Lee Hartmann, Alessio Caratti o Garatti, Dan M. Watson, David A. Neufeld, Ewine F. Van Dishoeck, Neal J. Evans II, Vinod Chandra Pathak, Samuel A. Federman, Tyler L. Bourke, Yao-Lun Yang, Guillem Anglada, Henrik Beuther, Leslie W. Looney, Rolf Kuiper, Pamela Klaassen, Pooneh Nazari, Bihan Banerjee, Joel Green, Sujay Vijay Jadhav, Mayra Osorio, B. Shridharan, Amelia M. Stutz, Thomas Stanke, John J. Tobin, Lukasz Tychoniec, Scott Wolk, Manya Arora. 2026-08-10. IPA: Morphology and Kinematics of Molecular Hydrogen Winds in Five Young Protostars across the Mass Spectrum Observed with JWST. https://arxiv.org/abs/2608.09920

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