A Caltech Library Service

The Depletion of Water During Dispersal of Planet-forming Disk Regions

Banzatti, A. and Pontoppidan, K. M. and Salyk, C. and Herczeg, G. J. and van Dishoeck, E. F. and Blake, G. A. (2017) The Depletion of Water During Dispersal of Planet-forming Disk Regions. Astrophysical Journal, 834 (2). Art. No. 152. ISSN 0004-637X.

[img] PDF - Published Version
See Usage Policy.

[img] PDF - Submitted Version
See Usage Policy.


Use this Persistent URL to link to this item:


We present a new velocity-resolved survey of 2.9 μm spectra of hot H_2O and OH gas emission from protoplanetary disks, obtained with the Cryogenic Infrared Echelle Spectrometer at the VLT (R ~ 96,000). With the addition of archival Spitzer-IRS spectra, this is the most comprehensive spectral data set of water vapor emission from disks ever assembled. We provide line fluxes at 2.9–33 μm that probe from the dust sublimation radius at ~0.05 au out to the region of the water snow line. With a combined data set for 55 disks, we find a new correlation between H_2O line fluxes and the radius of CO gas emission, as measured in velocity-resolved 4.7 μm spectra (R_(co)), which probes molecular gaps in inner disks. We find that H_2O emission disappears from 2.9 μm (hotter water) to 33 μm (colder water) as R_(co) increases and expands out to the snow line radius. These results suggest that the infrared water spectrum is a tracer of inside-out water depletion within the snow line. It also helps clarify an unsolved discrepancy between water observations and models by finding that disks around stars of M⋆ > 1.5 M⊙ generally have inner gaps with depleted molecular gas content. We measure radial trends in H_2O, OH, and CO line fluxes that can be used as benchmarks for models to study the chemical composition and evolution of planet-forming disk regions at 0.05–20 au. We propose that JWST spectroscopy of molecular gas may be used as a probe of inner disk gas depletion, complementary to the larger gaps and holes detected by direct imaging and by ALMA.

Item Type:Article
Related URLs:
URLURL TypeDescription Paper
Banzatti, A.0000-0003-4335-0900
Pontoppidan, K. M.0000-0001-7552-1562
Salyk, C.0000-0003-3682-6632
Herczeg, G. J.0000-0002-7154-6065
van Dishoeck, E. F.0000-0001-7591-1907
Blake, G. A.0000-0003-0787-1610
Additional Information:© 2017 The American Astronomical Society. Received 2016 September 9; revised 2016 November 6; accepted 2016 November 17; published 2017 January 11. We thank S. Antonellini and I. Kamp for providing water emission spectra from their ProDiMo model explorations, and for insightful discussions on water emission in disks and on its dependence on disk model parameters. We also thank A. Carmona for providing the CRIRES spectrum of HD139614. A.B. wishes to thank all colleagues who made this work possible through their pioneering work in infrared spectroscopy of disks. A.B. thanks Simon Bruderer for the seminal work he did in 2011–2012, which provided knowledge and tools to enable this work. A.B. acknowledges financial support by a NASA Origins of the Solar System grant No. OSS 11-OSS11-0120, a NASA Planetary Geology and Geophysics Program under grant NAG 5-10201. E.v.D. acknowledges European Union A-ERC grant 291141 CHEMPLAN. This work is partly based on observations made with ESO telescopes at the Paranal Observatory under programs 179.C-0151, 093.C-0432, 088.C-0666, 079.C-0349, 081.C-0833, 091.C-0671, 082.C-0491, and 088.C-0898. This work is partly based on observations made with the Spitzer Space Telescope, which is operated by the Jet Propulsion Laboratory, California Institute of Technology. This publication makes use of data products from the Wide-field Infrared Survey Explorer, which is a joint project of the University of California, Los Angeles, and the Jet Propulsion Laboratory/California Institute of Technology, funded by the National Aeronautics and Space Administration. This research has made use of the VizieR catalog access tool, CDS, Strasbourg, France. The original description of the VizieR service was published in A&AS 143, 23. This work is partly based on observations 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 the National Aeronautics and Space Administration. The observatory was made possible by the generous financial support of the W. M. Keck Foundation.
Group:Infrared Processing and Analysis Center (IPAC)
Funding AgencyGrant Number
NASAOSS 11-OSS11-0120
NASANAG 5-10201
European Research Council (ERC)291141 CHEMPLAN
W. M. Keck FoundationUNSPECIFIED
Subject Keywords:circumstellar matter – molecular processes – planets and satellites: formation – protoplanetary disks – stars: pre-main sequence
Issue or Number:2
Record Number:CaltechAUTHORS:20170110-095524207
Persistent URL:
Official Citation:A. Banzatti et al 2017 ApJ 834 152
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:73364
Deposited By: Tony Diaz
Deposited On:10 Jan 2017 18:53
Last Modified:09 Dec 2019 21:52

Repository Staff Only: item control page