High-Resolution Near-Infrared Images of the T Tauri Binary System XZ Tauri

We present a high-resolution (similar to 0.'' 1 = 14AU) H-band image of XZ Tau, a 0.'' 3-separated classical T Tauri binary system, taken with the Coronagraphic Imager with Adaptive Optics (CIAO) on the Subaru Telescope. We found a scattered light nebula extending to similar to 2.'' 4 from the secondary, XZ Tau S, in the northeast region of the binary. Its surface brightness is similar to 16.2 mag arcsec(-2) in the H-band, and decreases as r(-1.6 +/- 0.1). Combined with the HST/ACS polarimetric images and the [Fe II]lambda 1.644 mu m spectra taken with the Infrared Camera and Spectrograph (IRCS) on the Subaru Telescope, the elongated structure is identified as a wall of a cavity blown by the previously known blueshifted outflow. By a comparison with previous measurements, we estimated that the orbital period is 1010 +/- 260 yr and the total mass of the binary is 0.62 +/- 0.36 M-circle dot. The observed H-band magnitudes of both the primary and the secondary varied by as much as 1 mag over this decade. These H-band inconstancies may arise from a variable accretion rate and changing extinction toward each component.