The Disk and Accretion Shock of TW Hya
Abstract
We analyze the molecular hydrogen emission lines observed in HST/STIS and FUSE spectra of the nearest premain sequence star TW Hya. The molecular hydrogen lines are fluoresced by the Lyman alpha emission that likely comes from an accretion shock. We identify 140 molecular hydrogen emission lines and the 19 excitation paths that produce these lines. The molecular hydrogen is located near the inner edge of the disk with a temperature of 3000 K. The fluorescent emission allows us to reconstruct the Lyman alpha emission line profile and to study the properties of the stellar wind. We propose a model for the disk and accretion column of this star and discuss possible formation mechanisms of excited molecular hydrogen.
- Publication:
-
Stars as Suns : Activity, Evolution and Planets
- Pub Date:
- January 2004
- Bibcode:
- 2004IAUS..219..883H