JWST/NIRCam Imaging of Young Stellar Objects. III. Detailed Imaging of the Nebular Environment around the HL Tau Disk

Abstract

As part of the James Webb Space Telescope (JWST) Guaranteed Time Observation program “Direct Imaging of YSOs” (program ID 1179), we use JWST NIRCam’s direct imaging mode in F187N, F200W, F405N, and F410M to perform high-contrast observations of the circumstellar structures surrounding the protostar HL Tau. The data reveal the known stellar envelope, outflow cavity, and streamers, but do not detect any companion candidates. We detect scattered light from an inflowing spiral streamer previously detected in HCO ^+ by the Atacama Large Millimeter/submillimeter Array, and part of the structure connected to the c-shaped outflow cavity. For detection limits in planet mass we use BEX evolutionary tracks when M _p < 2 M _J and AMES-COND evolutionary tracks otherwise, assuming a planet age of 1 Myr (youngest available age). Inside the disk region, due to extended envelope emission, our point-source sensitivities are ∼5 mJy (37 M _J ) at 40 au in F187N and ∼0.37 mJy (5.2 M _J ) at 140 au in F405N. Outside the disk region, the deepest limits we can reach are ∼0.01 mJy (0.75 M _J ) at a projected separation ∼ 525 au.

Keywords

• Circumstellar envelopes
• Protoplanetary disks
• Exoplanet formation
• Direct imaging
• Star formation
• Infrared astronomy