Physical Sciences Division
Published March 13, 2024 | Version v1
Journal article Open

JWST-MIRI Spectroscopy of Warm Molecular Emission and Variability in the AS 209 Disk

Creators

  • 1. Harvard University
  • 2. Texas State University
  • 3. Space Telescope Science Institute
  • 4. University of Michigan
  • 5. Pennsylvania State University
  • 6. Vassar College
  • 7. Massachusetts Institute of Technology
  • 8. University of Chicago
  • 9. University of Leeds
  • 10. Pontificia Universidad Católica de Chile
  • 11. University of Virginia
  • 12. University of Tokyo
  • 13. University of Florida
  • 14. Leiden University
  • 15. National Astronomical Observatory of Japan
  • 16. Université Grenoble Alpes
  • 17. National Radio Astronomy Observatory
  • 18. Chinese Academy of Sciences

Description

We present MIRI Medium-resolution Spectrograph observations of the large, multi-gapped protoplanetary disk around the T Tauri star AS 209. The observations reveal hundreds of water vapor lines from 4.9–25.5 μm toward the inner ∼1 au in the disk, including the first detection of rovibrational water emission in this disk. The spectrum is dominated by hot (∼800 K) water vapor and OH gas, with only marginal detections of CO2, HCN, and a possible colder water vapor component. Using slab models with a detailed treatment of opacities and line overlap, we retrieve the column density, emitting area, and excitation temperature of water vapor and OH, and provide upper limits for the observable mass of other molecules. Compared to MIRI spectra of other T Tauri disks, the inner disk of AS 209 does not appear to be atypically depleted in CO2 nor HCN. Based on Spitzer Infrared Spectrograph observations, we further find evidence for molecular emission variability over a 10 yr baseline. Water, OH, and CO2 line luminosities have decreased by factors of 2–4 in the new MIRI epoch, yet there are minimal continuum emission variations. The origin of this variability is yet to be understood.

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Romero-Mirza_2024_ApJ_964_36.pdf

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Additional details

Identifiers

DOI
10.3847/1538-4357/ad20e9
Other
oai:uchicago.tind.io:13917

Funding

Simons Foundation
321183
Simons Foundation
321183FY19
National Science Foundation
1907653
National Aeronautics and Space Administration
HST-HF2-51460.001-A
National Aeronautics and Space Administration
HST-HF2-51512.001-A
National Aeronautics and Space Administration
NAS5-26555
CEA
CNES
European Research Council
101053020
FONDECYT
1221352
ANID
FB210003
ANID
NCN19_171
Science and Technology Facilities Council and UK Research and Innovation
ST/X001016/1
Science and Technology Facilities Council and UK Research and Innovation
MR/T040726/1
National Aeronautics and Space Administration
80NM0018D0004
National Aeronautics and Space Administration
NAS5-03127

UChicago Information

Division(s)
Physical Sciences Division
Department(s)
Geophysical Sciences