Astron. Astrophys. 348, 570-578 (1999)

GG Tauri: the ring world

S. Guilloteau ¹, A. Dutrey ¹ and M. Simon <sup>2

1</sup> Institut de Radio Astronomie Millimétrique, 300 Rue de la Piscine, F-38406 Saint Martin d'Hères, France
² Department of Physics and Astronomy, State University of New York, Stony Brook, NY 11794-3800, USA

Received 22 October 1998 / Accepted 16 April 1999

Abstract

We present sub-arcsecond images of the mm dust emission and ¹³CO J=2-1 line emission in the young quadruple system GG Tau. These observations unambiguously resolve the circumbinary disk of the close () binary system into two distinct components: an extremely dense, sharp-edged ring, surrounded by an extended disk. Continuum emission is also detected from the center of this structure; it probably arises in the small circumstellar disk or disks of the binary. The kinematic data show that the ring+disk system is in Keplerian rotation and yield the estimate for the mass of the binary stars. We derive the physical parameters of the ring and disk from these data and from new 2" resolution images of the HCO⁺ J=1-0 line and 3.4 mm continuum emission. The temperature in the ring + disk system is consistent with heating by the stellar light (including the IR excess coming from the inner disks). Comparison with the optical/NIR images indicates a disk thickness compatible with an hydrostatic equilibrium.

Key words: stars: binaries: close stars: circumstellar matter stars: individual: GG Tau stars: pre-main sequence radio continuum: stars radio lines: stars

Send offprint requests to: S. Guilloteau

Correspondence to: guillote@iram.fr

SIMBAD Objects

Contents

• 1. Introduction
• 2. Observations and data reduction
• 3. Observational results
  • 3.1. Structure of the continuum
  • 3.2. The ¹³CO and HCO⁺ line emission
• 4. Modelling
  • 4.1. Model description
  • 4.2. Dust emission and H₂ densities
  • 4.3. Kinematics of the circumbinary disk
  • 4.4. Gas temperature
  • 4.5. Molecular abundances
• 5. Discussion
  • 5.1. Geometrical thickness of the circumbinary ring
  • 5.2. Circumstellar disk emission
  • 5.3. Mass of the binary
• 6. Summary
• Acknowledgements
• References

© European Southern Observatory (ESO) 1999

Online publication: July 26, 1999
helpdesk.link@springer.de