Violent buckling benefits galactic bars
Abstract
Galactic bars are unstable to a vertical buckling instability which heats the disc and in some cases forms a boxy/peanut shaped bulge. We analyse the buckling instability as an application of classical Euler buckling followed by non-linear gravitational Landau damping in the collisionless system. We find that the buckling instability is dictated by the kinematic properties and geometry of the bar. The analytical result is compared to simulations of isolated galaxies containing the disc and dark matter components. Our results demonstrate that violent buckling does not destroy bars while a less energetic buckling can dissolve the bar. The discs that undergo gentle buckling remain stable to bar formation which may explain the observed bar fraction in the local Universe. Our results align with the results from recent surveys.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- February 2020
- DOI:
- 10.1093/mnras/stz3625
- arXiv:
- arXiv:1912.08190
- Bibcode:
- 2020MNRAS.492.2241C
- Keywords:
-
- methods: numerical;
- galaxies: evolution;
- galaxies: interactions;
- galaxies: kinematics and dynamics;
- Astrophysics - Astrophysics of Galaxies
- E-Print:
- 9 pages, 7 figures