1. Jets from the Upper Scorpius Variable Young Star System 2MASS J16075796-2040087 Via KECK/HIRES Spectro-astrometry
- Author
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Whelan, Emma, Keppler, Miriam, Turner, Neal, Pascucci, Ilaria, Hamden, Erika, Hoadley, Keri, and Fang, Min
- Subjects
Astrophysics - Solar and Stellar Astrophysics ,Astrophysics - Astrophysics of Galaxies - Abstract
2MASS J16075796-2040087 is a ~ 5 Myr young star in Upper Sco with evidence for accretion bursts on a timescale of about 15 days and, uncommonly for its age, outflows traced by multi-component forbidden emission lines (FELs). The accretion bursts may be triggered by a companion at ~ 4.6 au. We analyze HIRES spectra optimised for spectro-astrometry to better understand the origin of the several FEL velocity components and determine whether a MHD disk wind is present. The FEL high velocity component (HVC) traces an asymmetric, bipolar jet ~ 700 au long. The jet's position angle (PA) ~ 277 degrees is not perpendicular to the disk. The lower-velocity emission, classified previously as a disk wind low-velocity component (LVC), is found to have more in common with the HVC and overall it is not possible to identify a MHD disk wind component. The spectro-astrometric signal of the low velocity emission resembles those of jets and its density and ionisation fraction fall into the range of HVCs. We suggest a scenario where the accretion bursts due to the close companion power the jets past the age where such activity ends around most stars. The low-velocity emission here could come from a slow jet launched near the close companion and this emission would be blended with emission from the MHD wind., Comment: 24 pages, 14 figures, accepted for publication in the Astrophysical Journal
- Published
- 2024