Cosmic Physics 1
A.Y. 2023/2024
Learning objectives
The course aims at providing theoretical knowledge concerning interaction of radiation and matter and astrophysical fluid dynamics. Several radiation processes will be covered, such as dipole radiation, scattering Thomson and Compton, bremsstrahlung, and fundamentals of radiative transport. Then, the cours will consider the fluid equations, discussing astrophysically relevant equilibrium configurations (such as polytropic spheres), wave phenomena and instabilities, siuch as the gravitational instability
Expected learning outcomes
At the end of the course the student will:
1. Recognize the spectrum and emission features of the most important radiative processes in Astrophysics.
2. Solve the radiative transfer equation in simple geometries.
3. Apply when encessary the appropriate approximations, such as the radiative diffusion one.
4. Recognize and describe hydrostatic balance configurations in astrophysical context.
5. Derive the dispersion relation for sound waves and other dispersive waves.
6. Solve the shock conditions.
7. Recognize the fluid processes at play in the dynamics of astronomical systems, such as stars, the interstemmar medium and gas orbiting compact objects.
1. Recognize the spectrum and emission features of the most important radiative processes in Astrophysics.
2. Solve the radiative transfer equation in simple geometries.
3. Apply when encessary the appropriate approximations, such as the radiative diffusion one.
4. Recognize and describe hydrostatic balance configurations in astrophysical context.
5. Derive the dispersion relation for sound waves and other dispersive waves.
6. Solve the shock conditions.
7. Recognize the fluid processes at play in the dynamics of astronomical systems, such as stars, the interstemmar medium and gas orbiting compact objects.
Lesson period: First semester
Assessment methods: Esame
Assessment result: voto verbalizzato in trentesimi
Single course
This course cannot be attended as a single course. Please check our list of single courses to find the ones available for enrolment.
Course syllabus and organization
Single session
Responsible
Lesson period
First semester
In an emergency, lectures will be held synchronously via Zoom, using a virtual chalkboard. Lectures wil be recorded and made available on the Ariel website of the course.
Course syllabus
-) Introduction to fluid dynamics: Eulerian/Lagrangian approach. Reynolds transport theorem.
-) Continuity and Euler equations. Energy equation. Barotropic fluids.
-) Examples of hydrostatic equilibrium. Polytropic spheres.
-) Applications of polytropic spheres. Bonnor-Ebert spheres.
-) Perturbations in a fluid. Sound waves.
-) Shock waves. Rankine-Hugoniot relations.
-) Fluid Instabilities: thermal, convective, gravitational instability. Rayleigh-Taylor and Kelvin-Helmoltz instabilities.
-) Viscous fluids - Navier-Stokes equations.
-) Vorticity and turbulence. Kolmogorov's theory of turbulence.
-) Spherical accretion
-) Accretion disc theory: fundamental equations, stationary and time-dependent solutions.
-) Anomalous viscosity in accretion discs.
-) Gravitational instabilities in accretion discs.
-) Accretion discs around compact objects and around young stars: SED, line profiles.
-) Outburst and variability
-) Warped accretion discs
-) Continuity and Euler equations. Energy equation. Barotropic fluids.
-) Examples of hydrostatic equilibrium. Polytropic spheres.
-) Applications of polytropic spheres. Bonnor-Ebert spheres.
-) Perturbations in a fluid. Sound waves.
-) Shock waves. Rankine-Hugoniot relations.
-) Fluid Instabilities: thermal, convective, gravitational instability. Rayleigh-Taylor and Kelvin-Helmoltz instabilities.
-) Viscous fluids - Navier-Stokes equations.
-) Vorticity and turbulence. Kolmogorov's theory of turbulence.
-) Spherical accretion
-) Accretion disc theory: fundamental equations, stationary and time-dependent solutions.
-) Anomalous viscosity in accretion discs.
-) Gravitational instabilities in accretion discs.
-) Accretion discs around compact objects and around young stars: SED, line profiles.
-) Outburst and variability
-) Warped accretion discs
Prerequisites for admission
1. Fundamentals of mechanics (e.g. the two body problem, Kepler's laws)
2. Elents of calculus, in particular differential equations in one and more variables, Fourier transforms.
2. Elents of calculus, in particular differential equations in one and more variables, Fourier transforms.
Teaching methods
Chalkboard lectures.
Teaching Resources
2) Clarke-Carswell, "Astrophysical Fluid Dynamics", Cambridge University Press.
Assessment methods and Criteria
The exam is an oral discussion related to both broad topics of the course.
FIS/05 - ASTRONOMY AND ASTROPHYSICS - University credits: 6
Lessons: 42 hours
Professor:
Lodato Giuseppe
Educational website(s)
Professor(s)