Observations of the Star-Disk Interface: Search for Wind Origins
Author: Edwards, Suzan
Source: Astrophysics and Space Science, Volume 287, Numbers 1-4, 2003 , pp. 47-57(11)
Abstract:Energetic outflows provide a dramatic accompaniment to accretion disks in all stages of star formation. The low extinction toward Classical T Tauri stars offers an opportunity to probe the star-disk interface region to search for the launch site and acceleration region of accretion-driven winds. This search is complicated by the fact that the dominant sources of emission in the optical and ultraviolet are the funnel flows and accretion shocks associated with magnetospheric accretion. Thus the quest for inner wind diagnostics requires disentangling accretion and outflow processes from the same line profile. We discuss two tracers of a high velocity inner wind in stars with high disk accretion rates. One, a hot component, is traced by helium emission and must arise very close to the star. A second, cooler component, is traced by blueshifted absorption in strong resonance lines and arises further from the star, but still within about ten stellar radii. We present evidence that the character of both magnetospheric accretion and the inner wind may differ among stars with high and low disk accretion rates.
Document Type: Research Article
Affiliations: Five College Astronomy Department, Smith College, Northampton, MA 01063 USA
Publication date: 2003