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Arxiv: MINDS. JWST-MIRI Observations of a Spatially Resolved Atomic Jet and Polychromatic Molecular Wind Toward SY Cha Published: 9/17/2024 4:32:01 PM Updated: 12/2/2024 4:41:51 PM

Paper abstract: The removal of angular momentum from protostellar systems drives accretiononto the central star and may drive the dispersal of the protoplanetary disk.Winds and jets can contribute to removing angular momentum from the disk,though the dominant process remain unclear. To date, observational studies ofresolved disk winds have mostly targeted highly inclined disks. We report thedetection of extended H2 and [Ne II] emission toward the young stellar objectSY Cha with the JWST Mid-InfraRed Instrument Medium Resolution Spectrometer(MIRI-MRS). This is one of the first polychromatic detections of extended H2toward a moderately inclined, i=51.1 degrees, Class II source. We measure thesemi-opening angle of the H2 emission as well as build a rotation diagram todetermine the H2 excitation temperature and abundance. We find a widesemi-opening angle, high temperature, and low column density for the H2emission, all of which are characteristic of a disk wind. We derive a molecularwind mass loss rate of 3+-2e-9 Msun/yr, which is high compared to thepreviously derived stellar accretion rate of 6.6e-10 Msun/yr. This suggestseither that the stellar accretion and the disk wind are driven by differentmechanisms or that accretion onto the star is highly variable. Theseobservations demonstrate MIRI-MRS's utility in expanding studies of resolveddisk winds beyond edge-on sources.