
Course unit
GALACTIC DYNAMICS
SCP9086385, A.A. 2019/20
Information concerning the students who enrolled in A.Y. 2019/20
ECTS: details
Type 
ScientificDisciplinary Sector 
Credits allocated 
Educational activities in elective or integrative disciplines 
FIS/05 
Astronomy and Astrophysics 
6.0 
Course unit organization
Period 
Second semester 
Year 
1st Year 
Teaching method 
frontal 
Type of hours 
Credits 
Teaching hours 
Hours of Individual study 
Shifts 
Lecture 
6.0 
48 
102.0 
No turn 
Prerequisites:

Fundamentals of Astronomy, Astrophysics, Physics, and Numerical Methods. 
Target skills and knowledge:

Knowledge of the galactic structure and mass distribution using stellar dynamics in combination with photometric and kinematical data obtained from ground and spacebased observations. Ability to compare theoretical predictions from the fundamental equations of stellar hydrodynamics with observational data. 
Examination methods:

Oral exam on different topics discussed during lectures. 
Assessment criteria:

The student will be asked to use a correct terminology to describe the structure of galaxies, know the full program of the course, link the different topics discussed during lectures, properly compare observational data with theoretical predictions, and solve problems. 
Course unit contents:

1) Overview of the properties of galaxies: Morphology. Photometry. Kinematics. Scaling relations.
2) Potential theory: Gravitational potential. Poisson equation. Laplace equation. Gauss theorem. Potential energy. Potential energy tensor. Spherical systems. Newton theorems. Point mass. Homogeneous sphere. Hubble density profile. Powerlaw density profile. Axisymmetric systems. Logarithmic potential.
3) Orbits of the stars: Costants and integrals of the motion. Surfaces of section. Orbits in a static spherical potential. Orbits in a Keplerian potential. Orbits in a static axisymmetric potential. Motion in the meridional plane. Nearly circular orbits. Epicyclic approximation. Orbits in a twodimensional nonaxisymmetric nonrotating potential. Loop and box orbits. Stable and unstable orbits. Orbits in a twodimensional nonaxisymmetric rotating potential. Jacobi integral. Lagrangian points. Corotation. Families of orbits x1, x2, x3, x4. Introduction to the orbits in a threedimensional triaxial potential.
4) Collisionless systems: Geometric collisions. Strong collisions. Weak collisions. Crossing time. Relaxation time. Distribution function. Collisionless Boltzmann equation. Continuity equation. Euler equation. Jeans equations. Applications of the Jeans equations. Velocity ellipsoid. Asymmetric drift. Mass density in the Solar neighborhood. Velocity dispersions in spherical systems. Massanisotropy degeneracy. Spheroidal systems with isotropic velocity dispersions. Disk heating mechanisms. Virial theorem. Masstolight ratio of spherical systems. Rotation of elliptical galaxies. Jeans' theorem. Density profile from the distribution function. Spherical systems with isotropic velocity dispersion. Polytropes. Plummer sphere. Isothermal sphere. Singular isothermal sphere. King radius. King method to derive the masstolight ratio. King models. Tidal radius. Concentration parameter. Distribution function from the density profile. Eddington equation. Introduction to spherical systems with anisotropic velocity dispersion. Michie models. 
Planned learning activities and teaching methods:

Lectures at the blackboard and with the help of PowerPoint presentations on galactic structure and dynamics. Lectures are given in English. 
Additional notes about suggested reading:

All the slides of the lectures are available through the website of the course on the elearning platform of the Department of Physics and Astronomy "G. Galilei" (https://elearning.unipd.it/dfa/). Suggested textbook. 
Textbooks (and optional supplementary readings) 

Binney, James; Tremaine, Scott, Galactic Dynamics. Princeton, NJ: Princeton University Press, 1987.

Innovative teaching methods: Teaching and learning strategies
 Loading of files and pages (web pages, Moodle, ...)
Innovative teaching methods: Software or applications used
 Moodle (files, quizzes, workshops, ...)

