ASTROPHYSICS

The course aims to provide a sufficiently in-depth overview of the phenomena that take place in our Universe.

Particular attention will be paid to the quantitative description of the physical mechanisms that underlie these phenomena.

Due to the intrinsic interdisciplinarity of astrophysics, when necessary we will introduce, anticipating them in a heuristic way, concepts that will be fully addressed in other subjects later.

The approach used in class will be observational-theoretical.

 

Furthermore, in reference to the so-called Dublin Descriptors, this course will contribute to acquiring the following skills:

Knowledge and understanding

During the course the student will acquire a critical understanding of the most advanced developments in Astrophysics in both observational and theoretical aspects.

Ability to apply knowledge and understanding

During the course the student will refine his ability to identify the essential elements of the phenomena investigated in what constitutes the largest laboratory at our disposal: the Universe.

Making judgments

During the course the student will be encouraged to increase their ability to argue personal interpretations of what they have studied.

Communication skills

During the course the student will be encouraged to refine their ability to communicate the knowledge acquired with language skills, an ability that will be particularly important when they find themselves having to present their own research or review activity to an audience of specialists or lay people.

Learning skills

During the course the student will refine their ability to acquire adequate cognitive tools for the continuous updating of knowledge and the ability to access specialized scientific literature.

The exam will be carried out in oral mode; should the conditions require it, the learning assessment can also be carried out electronically.

The exam will aim to ascertain the overall level of knowledge acquired by the student and the ability to critically address the topics studied.

The attribution of the final grade will take into account equally the mastery shown in the qualitative and quantitative arguments.

 

The exam dates will be available in the Exam Calendar of the Bachelor's Degree Course in Physics.

Essential knowledge required to fully enjoy the course and to take the final exam:

- Differential and integral calculus of the functions of a variable

- Mechanics of material point systems.

- Thermodynamics.

- Electromagnetism

- Optics

1. Introduction

Methodology of investigation in astrophysics – Distance scale and units of measurement – ​​Observation instruments – Astronomical coordinate systems.

 

2 – The stars

- Generality

Fundamental parameters of stars: mass, radius and luminosity - The magnitude scale - Spectral classification of stars - The Hertzprung-Russell diagram - Luminosity classes.

– Stellar atmospheres

Radiation transport – Gray atmosphere model – Edge darkening - Formation of spectral lines – Boltzmann and Saha* equations – Einstein coefficients – Line broadening mechanisms – Abundance analysis.

- Internal structure

The equations of stellar structure – Mass-luminosity relationship – Nuclear fusion processes – Energy transport mechanisms – Schwarzschild criterion for the establishment of convection.

– Stellar evolution

The Virial Theorem* - The Jeans criterion for gravitational collapse and star formation - Pre- and post-main sequence evolution of stars - Fermi degenerate gas* – Final stages of evolution: white dwarfs, neutron stars and black holes - Pulsating variable stars.

 

3 – The Sun: a typical main sequence star

Solar atmosphere: photosphere, chromosphere, corona – Convection zone – Differential rotation – Alfvén's theorem* - Dynamo mechanism for the generation of magnetic fields – Emergence of magnetic flux tubes and solar activity (spots, faculae, protuberances, flares) - I solar neutrinos.

 

4 – The interstellar medium

Dense and diffuse interstellar clouds and the intercloud medium - Gas and dust - Cloud heating and cooling processes - H II regions - Interstellar chemistry in the gas phase and on the surface of the dust that acts as catalysts.

 

5 – Our galaxy

Morphology, dynamics and physical characteristics of the galaxy – Globular clusters and open clusters – Stellar populations – Dark matter - the supermassive black hole – Cosmic rays

6 – The galaxies

Hubble's morphological classification - Physical characteristics and formation processes of elliptical and disk galaxies - Active Galactic Nuclei (radio galaxies, QUASAR etc.) - Clusters and superclusters of galaxies - Extragalactic evidence of the presence of dark matter.

 

7 – Cosmology

Main observational evidence: Hubble's law of the expansion of the universe, the cosmic microwave background - Cosmological principle - Newtonian cosmology - Friedmann's equation and that of the cosmological fluid - Inflation and primordial fluctuations - Universe dominated by radiation, dominated by matter and the vacuum – Models of the Universe - Dark energy – The cosmological constant - Large and small scale anisotropies in the microwave background - Thermal history of the Universe.

1. GB Rybicki & A.P. Lightman: Radiative processes in Astrophysics, Wiley-VCH, New York (2004)

2. H. Karttunen et al.: Fundamental Astronomy, 5th ed, Springer Verlag, Berlin (2007)

 

For consultation

B.W. Carroll & D.A. Ostlie: An Introduction to Modern Astrophysics 2nd ed, Cambridge University Press, Cambridge (2007)

The exam will be carried out in oral mode; should the conditions require it, the learning assessment can also be carried out electronically.

The exam will aim to ascertain the overall level of knowledge acquired by the student and the ability to critically address the topics studied.

The attribution of the final grade will take into account equally the mastery shown in the qualitative and quantitative arguments.

The course topics are all possible subject to question.
The questions below do not constitute an exhaustive list but represent just some examples:
Telescopes, instruments and methods for astronomical measurements
Physics of Stellar Atmospheres
Photometric and spectroscopic properties of stars and galaxies
The Solar Corona
Star formation
Stellar structure equation
Stellar evolution
Chemistry of the Galaxy
Observational evidence of the expansion of the Universe