The Secular Evolution of Disk Structural Parameters

dc.creatorDebattista, Victor P.
dc.creatorMayer, Lucio
dc.creatorCarollo, C. Marcella
dc.creatorMoore, Ben
dc.creatorWadsley, James
dc.creatorQuinn, Thomas
dc.date2005-09-12
dc.date2006-07-08
dc.date.accessioned2026-07-07T11:57:15Z
dc.date.available2026-07-07T11:57:15Z
dc.descriptionWe 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]
dc.description18 pages, 21 figures, in emulateapj format. Published in ApJ. Animation accompanying submission available at http://www.astro.washington.edu/debattis/research/movies/movies.html. This new version corrects minor typos to match the published version. It also includes a figure 15 with new data and a section 7.1 discussing the requirements for SMBH formation from clump instabilities. appeared in ApJ, 645, 209
dc.identifierhttps://arxiv.org/abs/astro-ph/0509310
dc.identifierhttp://arxiv.org/abs/astro-ph/0509310
dc.identifierAstrophys.J.645:209-227,2006
dc.identifierdoi:10.1086/504147
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/205817
dc.subjectAstrophysics
dc.titleThe Secular Evolution of Disk Structural Parameters
dc.typetext

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