H_2O and OH gas in the terrestrial planet-forming zones of protoplanetary disks
Abstract
We present detections of numerous 10-20 μm H_2O emission lines from two protoplanetary disks around the T Tauri stars AS 205A and DR Tau, obtained using the InfraRed Spectrograph on the Spitzer Space Telescope. Follow-up 3-5 μm Keck NIRSPEC data confirm the presence of abundant water and spectrally resolve the lines. We also detect the P4.5 (2.934 μm) and P9.5 (3.179 μm) doublets of OH and ^(12)CO/^(13)CO v = 1 → 0 emission in both sources. Line shapes and LTE models suggest that the emission from all three molecules originates between ~0.5 and 5 AU, and so will provide a new window for understanding the chemical environment during terrestrial planet formation. LTE models also imply significant columns of H_2O and OH in the inner disk atmospheres, suggesting physical transport of volatile ices either vertically or radially, while the significant radial extent of the emission stresses the importance of a more complete understanding of nonthermal excitation processes.
Additional Information
© 2008 The American Astronomical Society. Received 2007 November 15; accepted 2008 January 31; published 2008 March 6. We are grateful to Joan Najita for discussions that prompted this work, and to the anonymous referee for a thoughtful review. Support was provided in part by the Spitzer Space Telescope Legacy Science Program (NASA contract numbers 1224608 and 1230779 issued by the Jet Propulsion Laboratory, California Institute of Technology under NASA contract 1407). K. M. P. is supported by NASA through Hubble Fellowship grant 01201.01 awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under contract NAS 5-26555. F. L. and E. v. D. are supported by NOVA and NWO-Spinoza grants. Some of the results herein were obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and NASA. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation.Attached Files
Published - SALapjl08.pdf
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Additional details
- Eprint ID
- 14306
- Resolver ID
- CaltechAUTHORS:20090526-151729278
- 1224608
- NASA
- 1230779
- NASA
- 01201.01
- NASA Hubble Fellowship
- NAS 5-26555
- NASA
- W. M. Keck Foundation
- Created
-
2009-05-27Created from EPrint's datestamp field
- Updated
-
2021-11-08Created from EPrint's last_modified field
- Caltech groups
- Division of Geological and Planetary Sciences