Herczeg, Gregory J.

Contact Email: gregoryh@casa.colorado.edu
Institute: JILA/University of Colorado
First Coauthor: Jeffrey L. Linsky
Institute: JILA/University of Colorado
Subject Area: Star Formation, Very Young Stars, T-Tauri, H-H Objects
Waveband: Far Ultraviolet
Technique: Spectroscopy
Presentation: Poster Display
Title: FUSE observations of molecular hydrogen in disks around T Tauri stars
Abstract: We analyze molecular hydrogen lines in the FUSE spectra of the pre-main sequence stars TW Hya, SU Aur, DX Cha, and V4046 Sgr. We detect Lyman band (B-X) H₂ lines in emission around the face-on systems TW Hya and V4046 Sgr. The emission is produced by Ly$\alpha$ pumping from excited rovibrational levels in the ground (X) electronic state. We observe Lyman band H₂lines from low-excitation levels in absorption against the O VI profiles of DX Cha and the edge-on system SU Aur. We conclude that UV H₂ emission and excitation are produced in the disk, rather than in a wind or infalling material.