A → magnetocentrifugal model for
→ accretion and → outflow in
→ protostars, which considers the interaction between the
→ magnetosphere of a
→ young stellar object and an &
rarr; accretion disk.
The model assumes that the → magnetic field
originates from the protostar, and the outflow is driven from a small region near the
inner edge of the disk, called X, where the inner disk corotates with
the star (→ corotation radius).
The accretion disk is → truncated
in its central region, that is the disk does not extend to the protostar. The matter
spiraling toward the protostar is either funneled by the magnetic field connecting
the star to the disk, or blown outward under the effect of
→ centrifugal force.
The X-wind model is able to account for many observations
in one fairly self-consistent model. The observations include time variable
accretion/wind phenomena in → T Tauri stars,
the slow rotation rates of T Tauri stars, protostellar X-ray activity,
and a number of the properties of → bipolar jets
and → molecular outflows
(F. H. Shu et al., 2000, in Protostars and Planets IV, V. Mannings et al. (eds.),
Tucson: Univ. Arizona Press, 789).
See also: X, referring to a configuration of the magnetic field where the lines of force
intersect with an “X” shape; → wind;
→ model.
