Dynamical friction in a gaseous medium with a large-scale magnetic field

Details Dynamical friction in a gaseous medium with a large-scale magnetic field Dynamical friction in a gaseous medium with a large-scale magnetic field

2011-11-28

arxiv.org/abs/1111.6632v1

Astronomy and Astrophysics

Astrophysics

Cosmology and Extragalactic Astrophysics

21 pages, 14 figures, accepted for publication in ApJ

Scientific paper

The dynamical friction force experienced by a massive gravitating body moving through a gaseous medium is modified by sufficiently strong large-scale magnetic fields. Using linear perturbation theory, we calculate the structure of the wake generated by, and the gravitational drag force on, a body traveling in a straight-line trajectory in a uniformly magnetized medium. The functional form of the drag force as a function of the Mach number (V_0/c_s, where V_0 is the velocity of the body and c_s the sound speed) depends on the strength of the magnetic field and on the angle between the velocity of the perturber and the direction of the magnetic field. In particular, the peak value of the drag force is not near Mach number 1 for a perturber moving in a sufficiently magnetized medium. As a rule of thumb, we may state that for supersonic motion, magnetic fields act to suppress dynamical friction; for subsonic motion, magnetic fields tend to enhance dynamical friction. For perturbers moving along the magnetic field lines, the drag force at some subsonic Mach numbers may be stronger than it is at supersonic velocities. We also mention the relevance of our findings to black hole coalescence in galactic nuclei.

Affiliated with

Also associated with

No associations

Rating

Dynamical friction in a gaseous medium with a large-scale magnetic field 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 Dynamical friction in a gaseous medium with a large-scale magnetic field, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Dynamical friction in a gaseous medium with a large-scale magnetic field will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-13373