Home Newsletter
News Books
Welcome to FreeScience.info Language/Lingua

Books 3054
· Book News
· Most clicked
· Least clicked

Search for a Book
HELP US TO HELP YOU
Add a new Book

Dynamics of secular evolution

book
Language:
Author: James Binney (Oxford University)
Url: http://arxiv.org/abs/1202.3403
Format: Ps, Pdf
Year: 2012
Category: Astrophysics of Galaxies
Pages: 43
Clicks: 783

Description
The text of lectures to the 2011 Tenerife Winter School. The School's theme was "Secular Evolution of Galaxies" and my task was to present the underlying stellar-dynamical theory. Other lecturers were speaking on the role of bars and chemical evolution, so these topics are avoided here. We start with an account of the connections between isolating integrals, quasiperiodicity and angle-action variables - these variables played a unifying role throughout the lectures. This leads on to the phenomenon of resonant trapping and how this can lead to chaos in cuspy potentials and phase-space mixing in slowly evolving potentials. Surfaces of section and frequency analysis are introduced as diagnostics of phase-space structure. Real galactic potentials include a fluctuating part that drives the system towards unattainable thermal equilibrium. Two-body encounters are only one source of fluctuations, and all fluctuations will drive similar evolution. We derive the orbit-averaged Fokker-Planck equation and relations that hold between the second-order diffusion coefficients and both the power spectrum of the fluctuations and the first-order diffusion coefficients. From the observed heating of the solar neighbourhood we show that the second-order diffusion coefficients must scale as J^{1/2}. We show that periodic spiral structure shifts angular momentum outwards, heating at the Lindblad resonances and mixing at corotation. The equation that would yield the normal modes of a stellar disc is first derived and then used to discuss the propagation of tightly-wound spiral waves. The winding up of such waves is explains why cool stellar discs are responsive systems that amplify ambient noise. An explanation is offered of why the Lin-Shu-Kalnajs dispersion relation and even global normal-mode calculations provide a very incomplete understanding of the dynamics of stellar discs.

Similar Books
Understanding Galaxy Formation and Evolution
Special Features of Galactic Dynamics
Guida all' Astrofisica Galattica
An Introduction to Galactic Chemical Evolution
Galaxy systems in the optical and infrared
Lopsided Spiral Galaxies
Introduction to Millimeter/Sub-Millimeter Astronomy
The First Galaxies
Protoplanetary Disks and Their Evolution
Formation of the First Galaxies: Theory and Simulations
Saas-Fee Lecture Notes: Multi-messenger Astronomy and Dark Matter
The First Stars and Galaxies - Basic Principles
Guida allí Astrofisica Galattica
Cosmological Evolution of Galaxies

Home |  Authors | About | Contact Us |  Email 
 Copyright © 2002-2013 FreeScience.info. 

Best viewed with Mozilla 1.X 1024x768
free scientific books