HIGH-RESOLUTION SPECTROSCOPY OF [Ne Ⅱ] EMISSION FROM TW HYDRAE

摘要

We present high-resolution echelle spectra of [Ne Ⅱ] 12.81 μm emission from the classical T Tauri star (CTTS) TW Hya, obtained with MICHELLE on Gemini North. The line is centered at the stellar radial velocity and has an intrinsic FWHM of 21 ±4 km s~(-1). The line width is broader than other narrow emission lines typically associated with the disk around TW Hya. If formed in a disk, the line broadening could result from turbulence in a warm disk atmosphere, Keplerian rotation at an average distance of 0.1 AU from the star, or a photoevaporative flow from the optically thin region of the disk. We place upper limits on the [Ne Ⅱ] emission flux from the CTTSs DP Tau and BP Tau.