96391 - ASTROPHYSICS OF GALAXIES

Learning outcomes

The course addresses in depth some fundamental topics of the astrophysics of galaxies, training the students to analyze and critically discuss papers relevant for the current research in the field. Starting from a dynamical description of the structure of galaxies, the course then examines the comparison between model and observed quantities, in particular acquired with recent observational campaigns; the evidence for dark matter, extended and in the form of central massive black holes; the properties of the hot interstellar medium; the physical origin of the main galaxy scaling laws.

Course contents

The aim of the course is a deep understanding of the structure of galaxies, especially of the "early" morphological type. The study focusses on modeling, and on its use to interpret observational results and evidences. In a first part, some concepts of stellar dynamics are reconsidered and the Jeans equations are derived, as a fundamental tool for the description of the stellar orbital properties and the mass distribution; the Jeans equations are then used in a number of applications, as the "detection" of dark mass components, and the relation between stellar orbital properties and shape. In a second part, the modeling is used to reproduce observed photometric and kinematical properties, with a particular attention to a proper comparison between observed and theoretical quantities. A few research papers are considered in depth, as representative of consolidated results and of currently debated subjects. In summary, the main investigated topics are the following:
1) the structure of the galaxies and of their different components; 2) the presence of dark matter: discovery and measurements; 3) the central supermassive black holes: discovery, measurement of their mass, effects on the host galaxy; 4) physical understanding of a few important scaling laws of galaxies, involving correlations between their structural/morphological/dynamical properties; 5) the stellar population in the scaling laws: roles of the IMF, age, metal abundance; 6) the relationship between the hot gas component and the stellar and dark mass components; galactic flows.

Readings/Bibliography

Research papers on various subjects will be indicated during the lessons; fundamental textbooks as reference for many topics are the following:

Binney, Tremaine: Galactic Dynamics, Princeton University Press, 1987 (2007, 2nd edition)

Binney, Merrifield: Galactic Astronomy, Princeton University Press, 1998

Greggio, Renzini: Stellar Populations. A user guide from low to high
redshift, Wiley, 2011

Ciotti, L. (2021). Introduction to Stellar Dynamics. Cambridge: Cambridge University Press.

Teaching methods

Oral lessons.

Assessment methods

Oral examination.

Teaching tools

Board and videoprojector.

Office hours

See the website of Silvia Pellegrini