Differential Rotation and Turbulence in Extended HI Disks

Details Differential Rotation and Turbulence in Extended HI Disks Differential Rotation and Turbulence in Extended HI Disks

1998-06-23

arxiv.org/abs/astro-ph/9806307v2

Astrophys.J. 511 (1999) 660-665

Astronomy and Astrophysics

Astrophysics

9 pages, no figures, to appear in ApJ, LaTeX uses aas2pp4.sty, eliminated duplicate paragraph

Scientific paper

10.1086/306728

When present, extended disks of neutral hydrogen around spiral galaxies show a remarkably uniform velocity dispersion of approx 6 km/s. Since stellar winds and supernovae are largely absent in such regions, neither the magnitude nor the constancy of this number can be accounted for in the classical picture in which interstellar turbulence is driven by stellar energy sources. Here we suggest that magnetic fields with strengths of a few microgauss in these extended disks allow energy to be extracted from galactic differential rotation through MHD driven turbulence. The magnitude and constancy of the observed velocity dispersion may be understood if its value is Alfvenic. Moreover, by providing a simple explanation for a lower bound to the gaseous velocity fluctuations, MHD processes may account for the sharp outer edge to star formation in galaxy disks.

Affiliated with

Also associated with

No associations

Rating

Differential Rotation and Turbulence in Extended HI Disks does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Differential Rotation and Turbulence in Extended HI Disks, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Differential Rotation and Turbulence in Extended HI Disks will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-20227