Turbulent motion in galactic \hii regions
C. R. O'Dell;
ApJ, 1986, 304, 767
ABSTRACT:An investigation of radial velocities across the face of NGC 1499, NGC 7000, and S252 reveals that the fine-scale
(turbulent) motions are well ordered from the limit of spatial resolution to the
full size of the nebulae.
As in higher spatial resolution studies of S142
and M17, analysis of the dispersion relation reveals that there is
agreement with Kolmogorov theory (1941).
However, study of the structure
function reveals the same result as found by Roy and Joncas (1985), that the
structure function increases with separation much more slowly than
theoretically expected, calling into question the application of Kolmogorov
theory.
The Roy-Joncas result that the fine-scale motion seems to begin at about
the sonic velocity are confirmed.
It is shown that a condition exists of
near equipartition of energies between fine-scale mass motion and thermal
gas motion, which raises the question of a possible link.
KEYWORDS: h ii regions, milky way galaxy, plasma turbulence, radial velocity, acoustic velocity, computational astrophysics, kolmogoroff theory, orion nebula
PERSOKEY:region hii, turbulence, ,
CODE: odell86