Astronomy 2

A.Y. 2020/2021
Overall hours
Learning objectives
Relying on the notions introduced in the course Astronomy I, this course
has the objective of providing the students with an overview of galactic
and extragalactic astrophysics, as well as of the main observationa
techniques used across the electromagnetic spectrum for ground and space
observations. An introduction is provided to the physical properties of
the interstellar medium, the dynamics of stellar clusters and of the
Milky Way, the properties of external galaxies, active galaxies and
galaxy clusters, as well as of the basics of big bang cosmology. At the
end the course comes back to the smaller scale of our Solar System, and
provides an updated discussion of extrasolar planets and their
implications for astrobiology.
Expected learning outcomes
Students at the end of the course are expected to reach the following
1. to be able to discuss the main characteristics of the instrumentation
adopted for astrophysical measurements across the electromagnetic
spectrum, from radio to gamma rays
2. to gain familiarity with different types of stellar clusters, their
dynamic, the information that can be extracted from an HR diagram
3. to be able to use the notions of interstellar extintion in distance
measurements, as well as to discuss the fundamental properties of the
gas and dust components of the interstellar medium
4. to be able to discuss the structure of our own Galaxy, its
diferential rotation, the evidence for a supermassive black hole at its
centre, the evidence of dark matter in the Galactic halo
5. to be able to classity galaxy, discuss star formation, as well as the
presence of dark matter form rotation curves, the nature and properties
of active agalactic nuclei
6. to be ale to discuss the physics of galaxy clusters, the evidence of
intracluster hot gas from X-ray observations
7. to acquire an initial vision of cosmology in the expanding universe,
including the basics of large scale distribution of matter and of cosmic
microwave background observations
8. to be able to discuss the main properties of our Solar System,
including the Earth-Moon system, terrestrial and giant planets, icy objects
9. to gain awareness of the current frontiers in the study of extrasolar
planets, including the data available on planets mass, density,
eccentricity, distance from central star, as well as of the implications
for potential life-supporting physical conditions
Course syllabus and organization

Single session

Lesson period
Second semester
In case of travel restrictions due to Covid-19, the course will be delivered entirely remotely. In this case, the lectures will be offered in virtual classrooms (zoom platform) in synchronous connection, with the possibility of real-time interaction between the students and the teacher.
Course syllabus
PART III - Telescopes and astronomical instruments
- Optical telescopes. Effective area, angular resolution. Seeing. Rifractive and reflective telescopes. Spectroscopy. Earth observatories. Hubble Space Telescope. Data handling.
- "Below the visible". IR and sub-mm astronomy. Microwave observations. Radioastronomy. Experiments and observations from the Earth. Space missions.
- "Above the visible". UV observations. X-ray astronomy. Gamma-ray astronomy. High-energy space telescopes.

PARTE IV - The Milky Way
- Stellar clusters. Kinds of clusters. Cluster dynamics. HR diagram for clusters. Stellar populations.lari.
- The interstellar medium. Interstellar extinction. Polarization. Diffusion and absorption. Interstellar dust. Dust grain physics. Interstellar gas. Interstellar molecules. Chemistry of the interstellar medium.
- Star formation. Gravitational collapse. Open problems. Molecular clouds and star formation. Protostars. HII regions.
- Our own Galaxy. Differential rotation of the Galaxy. Mass distribution. Rotation curve of the Milky Way. Distribution of the Galactic gas. Optical and radio observations. The Galactic Centre. The central supermassive black hole.

PARTE V - Extragalactic astronomy and cosmology
- Normal galaxies. Classification of galaxies. The spiral structure. Dark matter in galaxies. Measuring extragalactic distances. Galactic interactions.
- Large scale structures and galaxy clusters. Distribution of galaxies. Redshift surveys. Dynamics of galaxy clusters. Superclusters and voids. Properties of the intracluster medium. X-ray emission and the SZ effect. Merging of galaxy clusters. Dark matter in clusters.
- Active galaxies. Radio galaxies. Seyfert galaxies. Quasars. Black holes and active nuclei. Unified theory of active galaxies. Supermassive black holes and accretion disks. The Eddington luminosity.
- Cosmology. Olbers' paradox and the expansion. Hubble's law. Newtonian cosmology. Cosmology and general relativity. Cosmological redshift. Friedmann's equation. Cosmological parameters. Kinds of horizons. Current estimates for cosmological parameters.
- The early Universe. The Cosmic Microwave Background (CMB). Origin and properties of the CMB. Observations of the CMB. Primordial nucleosynthesis. Reionization. Structure formation. Large scale structures as a cosmological probe (BAO, mass function). Proofs of the existence of dark energy.

PART VI - The Solar System and extrasolar planets
- Introduction. The motion of planets and of the Moon. Structure of the Solar System
- The Earth-Moon system. Origin of the Earth. Dating methods. Plate tectonics. Temperature. A glimpse on the physics of the Earth's atmosphere. The magnetosphere. Tides. The Moon: its origin and structure. Open problems.
- Inner planets. Mercury. Venus. Mars. Earth observations. Exploration. Structure and surface of terrestrial planets. Atmospheres. Satellites.
- Outer planets. Characteristics. Inner structure and atmosphere. Rings: dynamics and properties. Satellites. Earth observations. Exploration.
- Minor bodies in the Solar System. Pluto. Comets. Meteorites. Asteroids.
- Astrobiology. Origin of the Solar System. Chemistry of the early Earth. Origin of life on Earth. Stability of terrestrial environment and biological evolution. Likeliness of finding life in the Solar System. Extrasolar planets. Observational prospects.
Prerequisites for admission
The student is assumed to be familiar with the basic knowledge from the Laurea Triennale in Physics and the contents of the course Astronomy I.
Teaching methods
During the lectures, students are invited to ask questions and contribute comments, to facilitate their critical and personal comprehension. Multi-media tools are regularly used, and made available to the students after each lecture.
Teaching Resources
-- Marc L. Kutner, "Astronomy: a Physical Perspective", Cambridge Univesity Press, 2003
-- D. Maoz, "Astrophysics in a nutshell", 2008, Princeton University Press
Furthermore, papers, materials, slides used during the lectures will be made available to the students.
Assessment methods and Criteria
A detailed discussion about some of the topics of the course, testing the critical understanding of the contents.
FIS/05 - ASTRONOMY AND ASTROPHYSICS - University credits: 6
Lessons: 42 hours
Ask the teacher
Laboratorio di Strumentazione Spaziale, Department of physics (via Celoria 16, Milano)