First cycle
degree courses
Second cycle
degree courses
Single cycle
degree courses
School of Science
Course unit
SCN1035990, A.A. 2017/18

Information concerning the students who enrolled in A.Y. 2017/18

Information on the course unit
Degree course Second cycle degree in
SC1173, Degree course structure A.Y. 2010/11, A.Y. 2017/18
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Degree course track ASTROMUNDUS [002PD]
Number of ECTS credits allocated 6.0
Type of assessment Mark
Course unit English denomination GALAXY DYNAMICS
Website of the academic structure
Department of reference Department of Physics and Astronomy
E-Learning website
Mandatory attendance
Language of instruction English
Single Course unit The Course unit can be attended under the option Single Course unit attendance
Optional Course unit The Course unit can be chosen as Optional Course unit

Teacher in charge ENRICO MARIA CORSINI FIS/05
Other lecturers GIUSEPPE GALLETTA FIS/05

ECTS: details
Type Scientific-Disciplinary Sector Credits allocated
Core courses 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 of
Individual study
Lecture 6.0 48 102.0 No turn

Start of activities 26/02/2018
End of activities 01/06/2018

Examination board
Board From To Members of the board
4 Commissione 01/10/2017 30/09/2018 CORSINI ENRICO MARIA (Presidente)
GALLETTA GIUSEPPE (Membro Effettivo)

Prerequisites: Basic knowledge of Physics, Astronomy, Astrophysics, and Numerical Analysis.
Target skills and knowledge: The course is devoted to study of the galactic structure using stellar dynamics in combination with photometric and kinematical data obtained from ground and space-based observations.
Examination methods: Oral exam.
Assessment criteria: Knowledge of the topics discussed during the lectures.
Course unit contents: 1. OVERVIEW OF THE PROPERTIES OF GALAXIES. Morphology. Photometry. Kinematics. Scaling relations.

2. POTENTIAL THEORY. Gravitational potential. Poisson’s equation. Laplace’s equation. Gauss’ theorem. Potential energy. Potential energy tensor. Spherical systems. Newton’s theorems. Point mass. Homogeneous sphere. Hubble density profile. Power-law density profile. Axisymmetric systems. Logarithmic potential.

3. THE 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 two-dimensional non-axisymmetric non-rotating potential. Loop and box orbits. Stable and unstable orbits. Orbits in a two-dimensional non-axisymmetric rotating potential. Jacobi’s integral. Lagrange’s points. Corotation. Families of orbits x1, x2, x3, x4. Introduction to the orbits in a three-dimensional triaxial potential.

4. COLLISIONLESS SYSTEMS. Geometric collisions. Strong collisions. Weak collisions. Crossing time. Relaxation time. Distribution function. Collisionless Boltzmann equation. Continuity equation. Euler’s equation. Jeans’ equations. Applications of the Jeans’ equations. Velocity ellipsoid. Asymmetric drift. Mass density in the Solar neighborhood. Velocity dispersions in spherical systems. Mass-anisotropy degeneracy. Spheroidal systems with isotropic velocity dispersions. Disk heating mechanisms. Virial theorem. Mass-to-light ratio of spherical systems. Rotation of elliptical galaxies. Jeans’ theorem. Density profile from the distribution function. Spherical systems with isotropic velocity dispersion. Polytropes. Plummer’s sphere. Isothermal sphere. Singular isothermal sphere. King’s radius. King’s method to derive the mass-to-light ratio. King’s models. Tidal radius. Concentration parameter. Distribution function from the density profile. Eddington’s equation. Introduction to spherical systems with anisotropic velocity dispersion. Michie’s models.
Planned learning activities and teaching methods: Lectures on topics of galactic dynamics.
Additional notes about suggested reading: All the slides of the lectures are available in the Moodle website of the course.
Textbooks (and optional supplementary readings)
  • Binney J., Tremaine S., Galactic Dynamics. Princeton, NJ: Princeton University Press, 1987. Cerca nel catalogo