First cycle
degree courses
Second cycle
degree courses
Single cycle
degree courses
School of Science
Course unit
SCN1032594, 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 ASTRONOMIA [001PD]
Number of ECTS credits allocated 6.0
Type of assessment Mark
Course unit English denomination ASTROPHYSICS OF GALAXIES
Website of the academic structure
Department of reference Department of Physics and Astronomy
Mandatory attendance
Language of instruction Italian
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

ECTS: details
Type Scientific-Disciplinary Sector Credits allocated
Core courses FIS/05 Astronomy and Astrophysics 6.0

Mode of delivery (when and how)
Period First semester
Year 1st Year
Teaching method frontal

Organisation of didactics
Type of hours Credits Hours of
Hours of
Individual study
Lecture 6.0 48 102.0 No turn

Start of activities 02/10/2017
End of activities 19/01/2018

Prerequisites: Basic knowledge of Astronomy, Astrophysics, Physics, and Numerical Methods.
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 equation. Laplace equation. Gauss theorem. Potential energy. Potential energy tensor. Spherical systems. Newton 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 nonaxisymmetric rotating potential. Jacobi integral. Lagrangian 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 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 sphere. Isothermal sphere. Singular isothermal sphere. King radius. King method to derive the mass-to-light 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 on galactic dynamics.
Additional notes about suggested reading: All the the slides of the lectures are available at the course Moodle website.
Textbooks (and optional supplementary readings)
  • Binney J., Tremaine S., Galactic Dynamics. Princeton, NJ: Princeton University Press, 1987. Cerca nel catalogo