CaltechAUTHORS
Published February 10, 2011 | Version Published
Journal Article Open

Fundamental Vibrational Transition of CO During the Outburst of EX Lupi in 2008

Creators

  • 1. ROR icon Max Planck Institute for Astronomy
  • 2. ROR icon Konkoly Observatory
  • 3. ROR icon European Southern Observatory
  • 4. ROR icon Max Planck Institute for Extraterrestrial Physics
  • 5. ROR icon University of Geneva
  • 6. ROR icon California Institute of Technology
  • 7. ROR icon Johns Hopkins University
  • 8. ROR icon Leiden University
  • 9. ROR icon University of Hawaii at Hilo

Abstract

We report monitoring observations of the T Tauri star EX Lupi during its outburst in 2008 in the CO fundamental band at 4.6–5.0 μm. The observations were carried out at the Very Large Telescope and the Subaru Telescope at six epochs from 2008 April to August, covering the plateau of the outburst and the fading phase to a quiescent state. The line flux of CO emission declines with the visual brightness of the star and the continuum flux at 5 μm, but composed of two subcomponents that decay with different rates. The narrow-line emission (50 kms^(−1) in FWHM) is near the systemic velocity of EX Lupi. These emission lines appear exclusively in v =1–0. The line widths translate to a characteristic orbiting radius of 0.4 AU. The broad-line component (FWZI ~ 150 km s^(−1)) is highly excited up to v ≤ 6. The line flux of the component decreases faster than the narrow-line emission. Simple modeling of the line profiles implies that the broad-line emitting gas is orbiting around the star at 0.04–0.4 AU. The excitation state, the decay speed of the line flux, and the line profile indicate that the broad-line emission component is physically distinct from the narrow-line emission component, and more tightly related to the outburst event.

Additional Information

© 2011 American Astronomical Society. Received 2010 April 17; accepted 2010 November 24; published 2011 January 13. We appreciate the anonymous referee for the constructive criticisms to improve the manuscript. We thank all the staff and crew of the VLT and Subaru for their valuable assistance in obtaining the data. M.G. thanks Takeshi Oka for patiently enlightening her in the thermodynamics of CO. M.G. also thanks Bringfried Stecklum and Andreas Seifahrt for instructive discussion and encouragement to finish the paper. Zs.R. was partly supported by MÖB/DAAD-841 Mobility Grant. A.C. acknowledges support from a Swiss National Science Foundation grant (PP002–110504). P.Á. acknowledges support from the grant OTKA K62304 of the Hungarian Scientific Research Fund. The research of Á.K. is supported by the Netherlands Organization for Scientific Research. A.S.A. acknowledges support from the Deutsche Forschungsgemeinschaft (DFG) grant SI 1486/1-1. We appreciate the hospitality of the Chilean and Hawaiian communities that made the research presented here possible.

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Additional details

Identifiers

Eprint ID
22930
Resolver ID
CaltechAUTHORS:20110316-093515491

Funding

Mobility Grant
MÖB/DAAD-841
Swiss National Science Foundation (SNSF)
PP002–110504
Hungarian Scientific Research Fund (OTKA)
OTKA K62304
Nederlandse Organisatie voor Wetenschappelijk Onderzoek (NWO)
Deutsche Forschungsgemeinschaft (DFG)
SI 1486/1-1

Dates

Created
2011-03-17
Created from EPrint's datestamp field
Updated
2021-11-09
Created from EPrint's last_modified field

Caltech Custom Metadata

Caltech groups
Division of Geological and Planetary Sciences (GPS)