Astronomy and Astrophysics – Astrophysics
Scientific paper
2005-09-12
Astrophys.J.645:209-227,2006
Astronomy and Astrophysics
Astrophysics
18 pages, 21 figures, in emulateapj format. Published in ApJ. Animation accompanying submission available at http://www.astr
Scientific paper
10.1086/504147
We present a comprehensive series of $N$-body as well as $N$-body + SPH simulations to study the secular evolution of the structure of disk galaxies. Our simulations are organized in a hierarchy of increasing complexity, ranging from rigid-halo collisionless simulations to fully live simulations with gas and star formation. Comparisons between the different types of simulations allow us to isolate the role of various physical mechanisms. We focus on the evolution of systems expected in a LCDM universe. Our goal is to examine which structural properties of disk galaxies may result from secular evolution rather than from direct hierarchical assembly. In the vertical direction, we find that various mechanisms can lead to heating. The strongest heating occurs during the vertical buckling instability of a bar. Among the consequences of this instability is the formation of peanut-shaped bulges which produce clear kinematic signatures when observed face-on. We find that bars are robust structures that are not destroyed by buckling. They can be destroyed instead by a central mass concentration but we find that this mass needs to be a large fraction of the total mass of the disk. We then study the evolution of stellar surface density profiles showing how angular momentum redistribution leads to increasing central densities and disk scale lengths and to profile breaks at large radii. The breaks in these simulations are in excellent agreement with observed breaks, even when the evolution is purely collisionless. Disk scale-lengths increase even when the total disk angular momentum is conserved; thus mapping halo angular momenta to scale-lengths is non-trivial. [Abridged]
Carollo Marcella C.
Debattista Victor P.
Mayer Lucio
Moore Ben
Quinn Thomas
No associations
LandOfFree
The Secular Evolution of Disk Structural Parameters 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 The Secular Evolution of Disk Structural Parameters, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The Secular Evolution of Disk Structural Parameters will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-704172