Magnetized Non-linear Thin Shell Instability: Numerical Studies in 2D

Details Magnetized Non-linear Thin Shell Instability: Numerical Studies in 2D Magnetized Non-linear Thin Shell Instability: Numerical Studies in 2D

2006-10-31

arxiv.org/abs/astro-ph/0610949v1

Astrophys.J.665:445-456,2007

Astronomy and Astrophysics

Astrophysics

12 pages, 17 figures, some of them at low resolution. Submitted to ApJ, comments welcome

Scientific paper

10.1086/519513

We revisit the analysis of the Non-linear Thin Shell Instability (NTSI) numerically, including magnetic fields. The magnetic tension force is expected to work against the main driver of the NTSI -- namely transverse momentum transport. However, depending on the field strength and orientation, the instability may grow. For fields aligned with the inflow, we find that the NTSI is suppressed only when the Alfv\'en speed surpasses the (supersonic) velocities generated along the collision interface. Even for fields perpendicular to the inflow, which are the most effective at preventing the NTSI from developing, internal structures form within the expanding slab interface, probably leading to fragmentation in the presence of self-gravity or thermal instabilities. High Reynolds numbers result in local turbulence within the perturbed slab, which in turn triggers reconnection and dissipation of the excess magnetic flux. We find that when the magnetic field is initially aligned with the flow, there exists a (weak) correlation between field strength and gas density. However, for transverse fields, this correlation essentially vanishes. In light of these results, our general conclusion is that instabilities are unlikely to be erased unless the magnetic energy in clouds is much larger than the turbulent energy. Finally, while our study is motivated by the scenario of molecular cloud formation in colliding flows, our results span a larger range of applicability, from supernovae shells to colliding stellar winds.

Affiliated with

Also associated with

No associations

Rating

Magnetized Non-linear Thin Shell Instability: Numerical Studies in 2D 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 Magnetized Non-linear Thin Shell Instability: Numerical Studies in 2D, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Magnetized Non-linear Thin Shell Instability: Numerical Studies in 2D will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-46551