Camryn Mullin

Topic

The Search for Young Planets with JWST/NIRCam

Department of Physics and Astronomy

Date & location

• Friday, August 9, 2024
• 8:30 A.M.
• Clearihue Building, Room B017

Examining Committee

Supervisory Committee

• Dr. Ruobing Dong, Department of Physics and Astronomy, University of Victoria (Supervisor)
• Dr. Doug Johnstone, Department of Physics and Astronomy, UVic (Member)

External Examiner

• Dr. Marshall Perrin, Assistant Astronomer, Space Telescope Science Institute

Chair of Oral Examination

• Dr. James Christian, School of Earth and Ocean Sciences, UVic
  Dr. Robin

Abstract

As part of the James Webb Space Telescope (JWST) Guaranteed Time Observation (GTO) program “Direct Imaging of YSOs” (program ID 1179), I used JWST NIRCam’s direct imaging mode with filters 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. I detect scattered light from an in-flowing 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, I use BEX evolutionary tracks when M_p < 2M_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, the 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 I can reach are ∼0.01 mJy (0.75 M_J) at a projected separation of ∼525 au.