TY - JOUR
T1 - High-resolution imaging of circumstellar gas and dust in UZ Tauri
T2 - Comparing binary and single-star disk properties
AU - Jensen, Eric L.N.
AU - Koerner, David W.
AU - Mathieu, Robert D.
PY - 1996/6
Y1 - 1996/6
N2 - We present λ = 1.3 and 3 mm aperture synthesis imaging of the multiple T Tauri system UZ Tauri. UZ Tau is a hierarchical triple composed of a single star, UZ Tau E, 530 AU distant from a 50 AU binary, UZ Tau W. Both dust and gas emission from the close binary are at least a factor of four lower than from the single star. Since UZ Tau E and W have similar stellar masses, luminosities, and ages, we conclude that the mass of dust and gas associated with UZ Tau W is reduced solely by the influence of a close companion. The disk emission from UZ Tau E is best interpreted as a circumstellar disk similar to those around other single T Tauri stars. In a 1″-resolution aperture synthesis map, CO (2→ 1) emission is coincident with the continuum peak and elongated with a size of 300 AU (FWHM); a velocity gradient is seen along the long axis, consistent with rotation in a gaseous disk. The emission is elongated at position angle 19°, the same as the PA of previous polarization measurements. A disk model fit to the continuum spectral energy distribution (SED) of UZ Tau E yields a disk mass of 0.06 M⊙. In contrast, no CO emission is detected from UZ Tau W, and its 1.3 mm continuum emission is unresolved in a 1″ (FWHM) beam (corresponding to a 70 AU radius). The small extent of the emission and dynamical considerations imply that the 50 AU binary cannot be surrounded by any appreciable circumbinary disk; its mm-wave emission is from circumstellar disks around one or both components. The mass of the circumstellar material is in the range 0.002-0.04 M⊙; the large uncertainty is due to the unknown temperature and surface density distributions of the material. The properties of the UZ Tau E disk are similar to those inferred for the early solar nebula; such a disk could give rise to a planetary system like our own. The mass of the UZ Tau W disk(s) is only marginally consistent with a "minimum mass solar nebula." The constraints on disk size in UZ Tau W indicate that reduced mm-wave flux may be linked to a disparity in the size of disks (and therefore of planetary systems) around single and binary stars.
AB - We present λ = 1.3 and 3 mm aperture synthesis imaging of the multiple T Tauri system UZ Tauri. UZ Tau is a hierarchical triple composed of a single star, UZ Tau E, 530 AU distant from a 50 AU binary, UZ Tau W. Both dust and gas emission from the close binary are at least a factor of four lower than from the single star. Since UZ Tau E and W have similar stellar masses, luminosities, and ages, we conclude that the mass of dust and gas associated with UZ Tau W is reduced solely by the influence of a close companion. The disk emission from UZ Tau E is best interpreted as a circumstellar disk similar to those around other single T Tauri stars. In a 1″-resolution aperture synthesis map, CO (2→ 1) emission is coincident with the continuum peak and elongated with a size of 300 AU (FWHM); a velocity gradient is seen along the long axis, consistent with rotation in a gaseous disk. The emission is elongated at position angle 19°, the same as the PA of previous polarization measurements. A disk model fit to the continuum spectral energy distribution (SED) of UZ Tau E yields a disk mass of 0.06 M⊙. In contrast, no CO emission is detected from UZ Tau W, and its 1.3 mm continuum emission is unresolved in a 1″ (FWHM) beam (corresponding to a 70 AU radius). The small extent of the emission and dynamical considerations imply that the 50 AU binary cannot be surrounded by any appreciable circumbinary disk; its mm-wave emission is from circumstellar disks around one or both components. The mass of the circumstellar material is in the range 0.002-0.04 M⊙; the large uncertainty is due to the unknown temperature and surface density distributions of the material. The properties of the UZ Tau E disk are similar to those inferred for the early solar nebula; such a disk could give rise to a planetary system like our own. The mass of the UZ Tau W disk(s) is only marginally consistent with a "minimum mass solar nebula." The constraints on disk size in UZ Tau W indicate that reduced mm-wave flux may be linked to a disparity in the size of disks (and therefore of planetary systems) around single and binary stars.
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U2 - 10.1086/117977
DO - 10.1086/117977
M3 - Article
AN - SCOPUS:0010661965
SN - 0004-6256
VL - 111
SP - 2431
EP - 2438
JO - Astronomical Journal
JF - Astronomical Journal
IS - 6
ER -