The aim of the course is twofold, i.e. to provide a general introduction, in the context of modern astronomy, to galaxies and clusters of galaxies, and to provide a deep knowledge of a few astrophysical issues connected with the equilibrium and stability of self-gravitating systems. This will allow students to understand the mechanisms of the internal dynamics of galaxies and galaxy systems. In particular, at the end of the course, the student must have obtained: D1: knowledge about galaxies and galaxy systems and about their internal dynamics, also to be able to discuss new ideas in research; D2: capability of applying this knowledge to related problems; D3: ability of interpreting related observational data, complex data and multi wavelength data too; D4: capability of transmitting their knowledge and/or conclusions about possible interpretations, with researchers in the field too; D5: capability of facing more advanced courses as (theoretical or observational) cosmology, and capability of going on with their studies independently, even using the appropriate and specific scientific literature.

No previous knowledge in Astrophysics is required. Knowledge from previous courses of basic physics (e.g., as obtained during the Italian LT in Physics). Students will take advantage of following the course of Stellar Astrophysics in the same semester.

BASICS AND PHENOMENOLOGY Astronomical measurements. Stars and their properties. Milky Way. Galaxies: morphological classification, mass and global properties, structure and surface photometry. Distance ladder and the Hubble low. Luminosity function. Galaxy clusters: classification, content of galaxies-hot gas-dark matter, mass, substructure. DYNAMICS OF SYSTEMS Potential Theory. Equilibria of collisionless systems. Stability of collisionless systems. Collisions and encounters of stellar systems. Galaxies and environmental effects. Collisions of galaxy clusters.

EXTRAGALACTIC ASTRONOMY, P.Schneider, Springer; GALACTIC DYNAMICS, Binney and Tremaine.
GALACTIC ASTRONOMY, Binney and Merrifield; FUNDAMENTAL ASTRONOMY, Karttunen, Krogel, Oja, et al..
Slides and notes of the teacher can be found on the web site moodle, in particular about topics poorly/not discussed in the texts.

See in https://moodle2.units.it about programs of the past years, in particular https:// moodle2.units.it/pluginfile.php/591054/mod_resource/content/1/progAstroGal2324.pdf%20.pdf
Here a summary.
BASICS AND PHENOMENOLOGY Astronomical measurements. Stars and their properties. Milky Way. Galaxies: morphological classification, mass and global properties, structure and surface photometry. Distance ladder and the Hubble low. Luminosity function. Galaxy clusters: classification, content of galaxies-hot gas-dark matter, mass, substructure. DYNAMICS OF SYSTEMS Potential Theory. Equilibria of collisionless systems. Stability of collisionless systems. Collisions and encounters of stellar systems. Galaxies and environmental effects. Collisions of galaxy clusters.

The following activities are part of the classroom: *formal lectures; *less formal parts with discussion, interruption encouraged; *slide presentations for the part about phenomenology description; *some examples of problem solution.
Possible seminars of experts. Possible changes to the above modalities due to an emergency are noted in the website of the Course of Study.

Other information in https://moodle2.units.it
Possible changes to the modalities of this course due to an emergency are noted in the website of the Course of Study.

The exams may be held in Italian or English, at the student's choice. Individual verbal examination. The students will be required to discuss, at least, three general topics. Further details will be required along the discussion. The examination lasts 30min.-1hour, depending on the student quality. The aim of the exam is to evaluate the knowledge of the topics of the course also in relation to concrete astronomical scenarios, the mastery of technical language, the ability to link the topics covered in the course, autonomous critical skills. Marks are expressed on 30/30 basis. (18-20 sufficient, 21-23 satisfactory, 24-26 good, 27-29 very good, 30 and 30L excellent). The teacher will give all the details about the exam methodology during the first lecture. Possible changes to the above modalities due to an emergency are noted in the website of the Course of Study.