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Centro de Astrofísica da Universidade do Porto

Near Infrared Lines as Diagnostics of Accretion in T Tauri Stars

D. F. M. Folha, J. P. Emerson

Abstract
We present results from a spectroscopic survey of Paβ & Brγ emission in a sample of T Tauri stars, mostly in the Taurus-Auriga complex. Velocity resolved spectra (Δv ∼ 15 km s-1) show that, of the 41 stars observed in Paβ emission, 34% display IPC redshifted absorptions, while, of the 29 stars observed in Brγ emission, 21% display IPC redshifted absorptions. The lines are broad (FWHM ∼ 200 km s-1) and lack blueshifted absorptions. These observations are consistent with the near infrared hydrogen lines forming predominantly in infalling material, as suggested by magnetospheric accretion column models. Radiative transfer calculations of the Paβ and Brγ line profiles in a very simplified, spherically symmetric situation are discussed.

Astrophysics and Space Science
Volume 261, Page 147
January 1999

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