Figures 1.19 and 1.20
show that the outflow found in globule CB 26 is rotating.
CB 26 is a Bok globule with bipolar NIR refrection
nebulae between which a very young T Tauri star and
AU-scale high-density disk are observed
(Fig.1.19).
Figure 1.20 shows the map of intensity-weighted velocity
(1st moment)

(1.7) |

in which we assume (i) the outflow is conical, (ii) gas element at in cylindrical coordinate was launched from a Keplerlian disk at conserving angular momentum, (iii) the radial expanding speed is simply proportional to the distance from the central star (eq.[1.8]). The assumption (ii) leads to (eq.[1.9) as the rotation speed is inversely proportional to the distance from the rotation axis . (iv) Density and temperature distributions are assumed as the density decreases with the distance in proportion to (eq.[1.10]), and the kinetic temperature decreases with the distance in proportion to (eq.[1.10]).

Comparing with a simple model (right panel), such global rotation motion is seen evidently only when the outflow is observed from edge-on.

Kohji Tomisaka 2009-12-10