96384 - Galaxy Formation and Evolution

Learning outcomes

The aim of the course is to provide the student with the fundamental knowledge of the extragalactic astrophysics, and the formation and evolution of galaxies in the cosmological framework. The student will learn the physical processes which explain the observed properties of galaxies and their evolution. In particular: (1) the main properties of our Galaxy, star forming galaxies, early-type galaxies and galaxy clusters in the present-day universe, (2) dark matter halos, (3) the cosmic evolution of baryonic matter, (4) the physics of galaxy formation, (5) the first luminous objects, (6) the observational studies of galaxy formation and evolution.

Course contents

The course aims to provide a coherent and modern overview of extragalactic astrophysics, the formation and evolution of galaxies in the cosmological context, and observational methods for studying high-redshift galaxies and the distant universe.

Main topics covered

• Introduction to galaxies
• Our Galaxy
• The Local Group
• Statistical properties of present-day galaxies
• Stellar population synthesis models
• Star-forming galaxies
• Early-type galaxies
• Galaxy clusters
• Dark matter halos
• Evolution of baryonic matter
• Formation of the first stars and primordial galaxies
• Physical processes of galaxy formation and evolution
• Observation of high-redshift galaxies
• Observational constraints on galaxy evolution
• Future prospects and thesis projects

Readings/Bibliography

Main Textbook

Introduction to Galaxy Formation and Evolution: From Primordial Gas to Present-Day Galaxies. Andrea Cimatti, Filippo Fraternali, Carlo Nipoti. Cambridge University Press.

For further reading:

Galaxy Formation and Evolution. Mo, van den Bosch & White. Cambridge University Press.

Additional readings will be recommended during the course. Moreover, the slides shown during the lectures are made available weekly via the Virtuale online platform. The slides can be used as a guide and outline for the topics covered in class, and as a supplement in cases where the textbook is not sufficient. Please note that the slides are not a substitute for the textbook, but rather complement it.

Detailed syllabus in the textbook Introduction to Galaxy Formation and Evolution:

1. Introduction

3. Present-Day Galaxies as a Benchmark for Evolutionary Studies

3.1 Morphology, 3.2 Spectral Energy Distributions, 3.3 Integrated Radiation from Galaxies, 3.4 Galaxy Spectra, 3.5 Statistical Distributions of Galaxy Properties.

4. Present-Day Star-Forming Galaxies

4.1 Stars, 4.2 The Interstellar Medium of Star-Forming Galaxies, 4.3 Mass Distribution, 4.4 Scaling Relations, 4.5 Starburst Galaxies, 4.6 The Milky Way (skip or just read p. 119).

5. Present-Day Early-Type Galaxies

5.1 Stars (skip eq. 5.1 and relative topic), 5.2 Diffuse Matter, 5.3 Mass Distribution, 5.4 Structural and Kinematic Scaling Relations.

6. The Environment of Present-Day Galaxies

6.1 Interacting Galaxies, 6.2 Groups of Galaxies, 6.3 The Local Group, 6.4 Clusters of Galaxies, 6.5 The Influence of the Environment on Galaxy Properties, 6.7 Baryon Budget.

7. Formation, Evolution and Properties of Dark Matter Halos

7.1 Observational Evidence for Dark Matter Halos, 7.2 Dark Matter and Structure Formation, 7.4.4 Hierarchical Merging of Cold Dark Matter Halos: Merger Trees and Merger Rates, 7.5 Structural and Kinematic Properties of Dark Matter Halos.

8. Main Ingredients of Galaxy Formation Theory

8.1 Thermal Properties of Astrophysical Gases, 8.2 Gas Accretion and Cooling in Dark Matter Halos, 8.3.9 The Initial Mass Function, 8.4 Gas Consumption and Evolution of the Interstellar Medium, 8.5 Chemical Evolution, 8.6 Theoretical Spectra of Evolving Galaxies, 8.7 Feedback from Stars (only the general/main topics), 8.8 Feedback from Active Galactic Nuclei (only the general/main topics), 8.9 Merging of Galaxies (only the general/main topics).

9. From Recombination to Reionisation

9.1 The Cosmological Recombination, 9.2 The Pregalactic Gas in the Dark Ages, 9.3 The Collapse of the Pregalactic Gas, 9.4 The Cooling of Primordial Gas, 9.5 Population III Stars, 9.6 From First Stars to First Galaxies, 9.7 The Formation of the First Massive Black Holes, 9.8 The Intergalactic Medium (only the general/main topics), 9.9 The Cosmological Reionisation (only the general/main topics), 9.10 Observing the Primeval Universe.

10. Theory of Galaxy Formation

10.1 Formation of Galaxy Components: Discs (only 10.1.4 and 10.1.7), 10.2 Formation of Galaxy Components: Bars and Pseudobulges, 10.3 Formation of Galaxy Components: Spheroids, 10.4 Formation of Galaxy Components: Stellar Halos, 10.5 Characteristic Scales in Galaxy Formation, 10.6 Quenching of Star Formation, 10.7 Assembly History of Present-Day Star-Forming Galaxies (no: “Cooling of the corona”, 10.7.5), 10.8 Assembly History of Present-Day Early-Type Galaxies, 10.11 Numerical Models of Galaxy Formation.

11. Observing Galaxy Evolution

11.1 The Main Observables of Galaxy Evolution, 11.2 The Difficult Observation of Distant Galaxies, 11.3 The Observation of Galaxy Evolution, 11.4 Summary.

Teaching methods

The lectures are oral and make use of both slides (as a visual help) and traditional blackboard for the proofs, examples and exercies. In addition, students are assigned some specialist articles to be read and discussed later in the classroom.

Assessment methods

To best prepare for exams, students are encouraged to attend the course regularly until its end. In the event of absences or working students, missed lecture material can be made up using slides made available weekly online. Exams are oral, taken at the blackboard (except for special needs) and last approximately 30-40 minutes. Three to four questions are asked during the exams to assess learning and, above all, the student's ability to coherently connect the various course topics. The exam assesses both general knowledge and the student's ability to perform the physical and mathematical proofs illustrated by the instructor during the course. This is all aimed at encouraging and activating a process of informed self-assessment among students. The exam results in a final grade expressed out of 30, with the following scale: 18-20: very limited preparation and limited independent analysis; 21-25: intermediate preparation and moderate independent analysis; 26-29: extensive but not complete preparation, good/very good independent analysis; 30-30L: complete preparation and excellent/excellent independent analysis. Please note that a grade can be declined a maximum of two times. Students can register for exams through the Almaesami platform. Students with learning disabilities or temporary or permanent disabilities: please contact the relevant University office promptly (https://site.unibo.it/studenti-con-disabilita-e-dsa/it ). The office will advise students of possible adjustments, that will be submitted to the professor for approval 15 days in advance. He/she will evaluate their suitability also in relation to the academic objectives of the course.

Teaching tools

Traditional blackboard. Projector for computer presentations. Projection of the computer screen in the classroom to show websites, animations, and images on specific topics.

Office hours

See the website of Andrea Cimatti