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Title: A HUBBLE SPACE TELESCOPE SURVEY OF H{sub 2} EMISSION IN THE CIRCUMSTELLAR ENVIRONMENTS OF YOUNG STARS

Abstract

The formation timescale and final architecture of exoplanetary systems are closely related to the properties of the molecular disks from which they form. Observations of the spatial distribution and lifetime of the molecular gas at planet-forming radii (a < 10 AU) are important for understanding the formation and evolution of exoplanetary systems. Toward this end, we present the largest spectrally resolved survey of H{sub 2} emission around low-mass pre-main-sequence stars compiled to date. We use a combination of new and archival far-ultraviolet spectra from the Cosmic Origins Spectrograph and Space Telescope Imaging Spectrograph instruments on the Hubble Space Telescope to sample 34 T Tauri stars (27 actively accreting Classical T Tauri Stars and 7 non-accreting Weak-lined T Tauri Stars) with ages ranging from {approx}1 to 10 Myr. We observe fluorescent H{sub 2} emission, excited by Ly{alpha} photons, in 100% of the accreting sources, including all of the transitional disks in our sample (CS Cha, DM Tau, GM Aur, UX Tau A, LkCa 15, HD 135344B, and TW Hya). The spatial distribution of the emitting gas is inferred from spectrally resolved H{sub 2} line profiles. Some of the emitting gas is produced in outflowing material, but the majority of H{sub 2}more » emission appears to originate in a rotating disk. For the disk-dominated targets, the H{sub 2} emission originates predominately at a {approx}< 3 AU. The emission line widths and inner molecular radii are found to be roughly consistent with those measured from mid-IR CO spectra.« less

Authors:
; ;  [1];  [2]; ;  [3];  [4];  [5];  [6];  [7]
  1. Center for Astrophysics and Space Astronomy, University of Colorado, 389 UCB, Boulder, CO 80309 (United States)
  2. Max-Planck-Institut fuer extraterrestriche Physik, Postfach 1312, D-85741 Garching (Germany)
  3. LUTH and UMR 8102 du CNRS, Observatoire de Paris, Section de Meudon, Place J. Janssen, F-92195 Meudon (France)
  4. Department of Physics and Astronomy, University of Leicester, Leicester LE1 7RH (United Kingdom)
  5. Department of Astronomy, University of Michigan, 830 Dennison Building, 500 Church Street, Ann Arbor, MI 48109 (United States)
  6. Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, MS-78, Cambridge, MA 02138 (United States)
  7. JILA, University of Colorado and NIST, 440 UCB, Boulder, CO 80309 (United States)
Publication Date:
OSTI Identifier:
22092359
Resource Type:
Journal Article
Journal Name:
Astrophysical Journal
Additional Journal Information:
Journal Volume: 756; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0004-637X
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ACCRETION DISKS; ASTRONOMY; ASTROPHYSICS; CARBON MONOXIDE; EMISSION SPECTRA; FAR ULTRAVIOLET RADIATION; FLUORESCENCE; HYDROGEN; INFRARED SPECTRA; INTERMEDIATE INFRARED RADIATION; LIFETIME; LINE WIDTHS; LYMAN LINES; MAIN SEQUENCE STARS; MASS; PLANETS; PROTOPLANETS; SPATIAL DISTRIBUTION; STAR ACCRETION; T TAURI STARS

Citation Formats

France, Kevin, Schindhelm, Eric, Brown, Alexander, Herczeg, Gregory J., Abgrall, Herve, Roueff, Evelyne, Alexander, Richard D., Bergin, Edwin A., Brown, Joanna M., Linsky, Jeffrey L., and Yang Hao, E-mail: kevin.france@colorado.edu. A HUBBLE SPACE TELESCOPE SURVEY OF H{sub 2} EMISSION IN THE CIRCUMSTELLAR ENVIRONMENTS OF YOUNG STARS. United States: N. p., 2012. Web. doi:10.1088/0004-637X/756/2/171.
France, Kevin, Schindhelm, Eric, Brown, Alexander, Herczeg, Gregory J., Abgrall, Herve, Roueff, Evelyne, Alexander, Richard D., Bergin, Edwin A., Brown, Joanna M., Linsky, Jeffrey L., & Yang Hao, E-mail: kevin.france@colorado.edu. A HUBBLE SPACE TELESCOPE SURVEY OF H{sub 2} EMISSION IN THE CIRCUMSTELLAR ENVIRONMENTS OF YOUNG STARS. United States. https://doi.org/10.1088/0004-637X/756/2/171
France, Kevin, Schindhelm, Eric, Brown, Alexander, Herczeg, Gregory J., Abgrall, Herve, Roueff, Evelyne, Alexander, Richard D., Bergin, Edwin A., Brown, Joanna M., Linsky, Jeffrey L., and Yang Hao, E-mail: kevin.france@colorado.edu. 2012. "A HUBBLE SPACE TELESCOPE SURVEY OF H{sub 2} EMISSION IN THE CIRCUMSTELLAR ENVIRONMENTS OF YOUNG STARS". United States. https://doi.org/10.1088/0004-637X/756/2/171.
@article{osti_22092359,
title = {A HUBBLE SPACE TELESCOPE SURVEY OF H{sub 2} EMISSION IN THE CIRCUMSTELLAR ENVIRONMENTS OF YOUNG STARS},
author = {France, Kevin and Schindhelm, Eric and Brown, Alexander and Herczeg, Gregory J. and Abgrall, Herve and Roueff, Evelyne and Alexander, Richard D. and Bergin, Edwin A. and Brown, Joanna M. and Linsky, Jeffrey L. and Yang Hao, E-mail: kevin.france@colorado.edu},
abstractNote = {The formation timescale and final architecture of exoplanetary systems are closely related to the properties of the molecular disks from which they form. Observations of the spatial distribution and lifetime of the molecular gas at planet-forming radii (a < 10 AU) are important for understanding the formation and evolution of exoplanetary systems. Toward this end, we present the largest spectrally resolved survey of H{sub 2} emission around low-mass pre-main-sequence stars compiled to date. We use a combination of new and archival far-ultraviolet spectra from the Cosmic Origins Spectrograph and Space Telescope Imaging Spectrograph instruments on the Hubble Space Telescope to sample 34 T Tauri stars (27 actively accreting Classical T Tauri Stars and 7 non-accreting Weak-lined T Tauri Stars) with ages ranging from {approx}1 to 10 Myr. We observe fluorescent H{sub 2} emission, excited by Ly{alpha} photons, in 100% of the accreting sources, including all of the transitional disks in our sample (CS Cha, DM Tau, GM Aur, UX Tau A, LkCa 15, HD 135344B, and TW Hya). The spatial distribution of the emitting gas is inferred from spectrally resolved H{sub 2} line profiles. Some of the emitting gas is produced in outflowing material, but the majority of H{sub 2} emission appears to originate in a rotating disk. For the disk-dominated targets, the H{sub 2} emission originates predominately at a {approx}< 3 AU. The emission line widths and inner molecular radii are found to be roughly consistent with those measured from mid-IR CO spectra.},
doi = {10.1088/0004-637X/756/2/171},
url = {https://www.osti.gov/biblio/22092359}, journal = {Astrophysical Journal},
issn = {0004-637X},
number = 2,
volume = 756,
place = {United States},
year = {2012},
month = {9}
}