Aperture Synthesis 13CO (J = 1-0) Observations of the Molecular Gas around DG Tauri: Evidence for a Dispersing Gas Disk

Abstract

view Abstract Citations (37) References (36) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Aperture Synthesis 13CO (J = 1-0) Observations of the Molecular Gas around DG Tauri: Evidence for a Dispersing Gas Disk Kitamura, Yoshimi ; Kawabe, Ryohei ; Saito, Masao Abstract We made aperture synthesis 13CO (J = 1-0) observations of the molecular gas around a young star DG Tau, using the Nobeyama Millimeter Array. We have detected the gas in the velocity range υLSR = 4.3-7.3 km s-1, and have revealed the velocity structure of the gas with velocity resolution 0.43 km s - 1 The molecular gas around DG Tau is found to have a disklike structure, with the major axis perpendicular to the blueshifted optical jet ejected from the star. The radius, mass, and inclination angle of the disk are estimated to be ∼2800 AU, 0.03 Msun, and 40°, respectively. It is noted that an expanding motion is distinct in the disk. The expanding velocity is about 1.5 km s-1, which is larger than both the Kepler and free-fall velocities around DG Tau. Since the mechanical luminosity of the expanding motion is estimated to be 6 × 10-4 Lsun, much smaller than the stellar luminosity of ∼1 Lsun, the expansion is possibly driven by the stellar wind from the central star. The disk model for the expanding gas around DG Tau is quite consistent with the structures of the reflection nebula and the blueshifted optical jet that were observed around the star. It would be reasonable to make the interpretation that the outer part of the large gas disk around the star, or the disk-shaped remnant of the envelope surrounding the star, -is now being dispersed owing to the stellar wind during the evolution of a large protostellar disk into a compact protoplanetary one, because DG Tau has a flat spectral energy distribution and is considered to be evolving from a protostar to a T Tauri star. Publication: The Astrophysical Journal Pub Date: January 1996 DOI: 10.1086/176728 Bibcode: 1996ApJ...457..277K Keywords: ISM: JETS AND OUTFLOWS; STARS: MASS LOSS; STARS: PRE-MAIN-SEQUENCE; STARS: CIRCUMSTELLAR MATTER; ISM: MOLECULES; STARS: INDIVIDUAL CONSTELLATION NAME: DG TAURI full text sources ADS | data products SIMBAD (5)