R. Azevedo, D. F. M. Folha, J. F. Gameiro, N. Calvet
Abstract
We have conducted a spectro-astrometric (SA) analysis of high spectral resolution data of the near infrared HeI 10830Å and Paγ lines in the nearby classical T Tauri star TW Hya. We find clear position offsets associated to the blueshifted absorption part of the HeI 10830Å P Cygni profile. The derived spatial feature extend up to 50 mas (2.8 AU at TW Hya distance) in two opposite directions. By using simple exploratory models we show that this feature can not be produced by the same stellar wind which produces the P Cygni profile. Instead, we are able to reproduce the observed blueshifted SA profile with emission from a disk wind. The production of SA artifacts through instrumental effects was examined. Artifact models have difficulties in fitting both the PSF and the angular scale of the observed position spectra offsets, suggesting that the signal may be real.
Keywords
star formation, spectral analysis, spectral line shift
COOL STARS, STELLAR SYSTEMS AND THE SUN: Proceedings of the 15th Cambridge Workshop on Cool Stars, Stellar Systems and the Sun.
AIP Conference Proceedings, Number 1094, Page 345
2009 February
