Astronomy and Astrophysics – Astrophysics
Scientific paper
1998-11-02
Astrophys. J 519, 590 (1999)
Astronomy and Astrophysics
Astrophysics
20 pages, Latex, 8 embedded figures, version to be published in The Astrophys. J
Scientific paper
10.1086/307402
General analytic arguments lead us to expect that in the modified dynamics (MOND) self-gravitating disks are more stable than their like in Newtonian dynamics. We study this question numerically, using a particle-mesh code based on a multi-grid solver for the (nonlinear) MOND field equation. We start with equilibrium distribution functions for MOND disk models having a smoothly truncated, exponential surface-density profiles and a constant Toomre $Q$ parameter. We find that, indeed, disks of a given ``temperature'' are locally more stable in MOND than in Newtonian dynamics. As regards global instability to bar formation, we find that as the mean acceleration in the disk is lowered, the stability of the disk is increased as we cross from the Newtonian to the MOND regime. The degree of stability levels off deep in the MOND regime, as expected from scaling laws in MOND. For the disk model we use, this maximum degree of stability is similar to the one imparted to a Newtonian disk by a halo three times as massive at five disk scale lengths.
Brada Rafael
Milgrom Mordehai
No associations
LandOfFree
Stability of disk galaxies in the modified dynamics 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 Stability of disk galaxies in the modified dynamics, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Stability of disk galaxies in the modified dynamics will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-446699