Notsu, S, Nomura, H, Ishimoto, D et al. (4 more authors) (2017) Candidate Water Vapor Lines to Locate the H₂O Snowline Through High-dispersion Spectroscopic Observations. II. The Case of a Herbig Ae Star. Astrophysical Journal, 836 (1). 118. ISSN 0004-637X
Abstract
Observationally measuring the location of the H₂O snowline is crucial for understanding planetesimal and planet formation processes, and the origin of water on Earth. In disks around Herbig Ae stars (T * ~ 10,000 K, M * > 2.5Msun), the position of the H₂O snowline is farther from the central star compared with that around cooler and less massive T Tauri stars. Thus, the H₂O emission line fluxes from the region within the H₂O snowline are expected to be stronger. In this paper, we calculate the chemical composition of a Herbig Ae disk using chemical kinetics. Next, we calculate the H₂O emission line profiles and investigate the properties of candidate water lines across a wide range of wavelengths (from mid-infrared to submillimeter) that can locate the position of the H₂O snowline. Those lines identified have small Einstein A coefficients (~10¯⁶ - 10¯³ s¯¹) and relatively high upper-state energies (~1000 K). The total fluxes tend to increase with decreasing wavelengths. We investigate the possibility of future observations (e.g., ALMA, SPICA/SMI-HRS) locating the position of the H₂O snowline. Since the fluxes of those identified lines from Herbig Ae disks are stronger than those from T Tauri disks, the possibility of a successful detection is expected to increase for a Herbig Ae disk.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | (c) 2017. The American Astronomical Society. All rights reserved. This is an author produced version of a paper published in The Astrophysical Journal. Uploaded in accordance with the publisher's self-archiving policy. |
Keywords: | astrochemistry; infrared: planetary systems; ISM: molecules; protoplanetary disks; stars: formation; submillimeter: planetary systems |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Physics and Astronomy (Leeds) > Astrophysics (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 08 Mar 2017 14:53 |
Last Modified: | 31 Jan 2018 17:15 |
Published Version: | https://doi.org/10.3847/1538-4357/836/1/118 |
Status: | Published |
Publisher: | American Astronomical Society |
Identification Number: | 10.3847/1538-4357/836/1/118 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:113171 |