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Centro de Astrofísica da Universidade do Porto

Extended wind in jetless classical T Tauri star TW Hya

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 10830°A and Pa lines in the nearby classical T Tauri star TW Hya. We find clear position offsets associated to the blueshifted absorption part of the HeI 10830°A P Cygni profile. The derived spatial feature extend up to 50 mas (2.8AU 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.

The Astrophysical Journal
Volume 670, Page 1234
December 2007

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