Cosmic physics 1

A.Y. 2016/2017
6
Max ECTS
48
Overall hours
SSD
FIS/05
Language
Italian
Learning objectives
Lo scopo del corso è di approfondire la conoscenza di diversi processi fisici di rilevanza astrofisica (processi radiativi, astrofisica dei fluidi) e di applicare tali conoscenze al contesto specifico della formazione stellare e planetaria. Alla fine del Corso, gli studenti dovrebbero essere in grado di: (i) analizzare e risolvere problemi riguardanti l'interazione tra la materia e la radiazione elettromagnetica, (ii) analizzare e risolvere problemi di dinamica dei fluidi, in particolare di fluidi autogravitanti, (iii) riconoscere le caratteristiche fisiche delle principali classi di oggetti proto-stellari e delle nubi molecolari (iv) identificare e caratterizzare i processi fisici alla base dell'evoluzione delle nubi molecolari e dei dischi protostellari.
Expected learning outcomes
Undefined
Course syllabus and organization

Single session

Responsible
Lesson period
Second semester
Course syllabus
-) Fundamental Physical Processes
-) Interaction of radiation and matter:
· The electromagnetic field. Radiation from moving charges: Larmor's formula, dipole approximation.
· Thomson scattering, Rayleigh scattering.
· Bremsstrahlung: single charge spectrum, spectrum of a thermal electron population.
· Cyclotron and synchrotron radiation. Compton scattering and inverse Compton scattering.
· Emission and absorption coefficients. Equation of radiative transfer. Optical depth.
· Blackbody radiation. Kirchhoff's theorem. Einstein's coefficients.
-) Astrophysical Fluid Dynamics:
· Fluid equations. Eulerian and Lagrangian approaches.
· Continuity equation, Euler's equation, equation of state. Poisson's equation. Energy equation.
· Hydrostatic equilibrium: isothermal atmosphere, self-gravitating isothermal slab, polytropic spheres, Bonnor-Ebert spheres.
· Waves and fluid instabilities: sound waves, shock waves. Thermal instability, Gravitational instability. Overview of Rayleigh-Taylor and Kelvin-Helmholtz instabilities.
· Viscous fluids: Navier-Stokes equations.
· Turbolence: overview of Kolmogorov theory.
· Accretion discs theory.

-) Star formation
· Introduction to star formation: molecular clouds and molecular cloud cores. Scale relations for molecular clouds. The opacity limit for fragmentation. Formation and evolution of molecular clouds.
· Spectral classification of young stellar objects: Class I, II and III sources.
· Protostellar accretion discs: discs around T Tauri stars, discs in FU Orionis objects.
· Star formation for high mass stars and brown dwarfs.

-) Planet formation
· Introduction: extra-solar planets observations. Statistical properties of extra-solar planets.
· Models for extra-solar planet formation: the 'core accretion' model, the gravitational instability model.
· (Migration during planet formation: migration involving the solid component in protostellar discs, Type I and Type II migration)
FIS/05 - ASTRONOMY AND ASTROPHYSICS - University credits: 6
Lessons: 48 hours
Professor: Lodato Giuseppe
Professor(s)
Reception:
Monday 14.00-15.00 (upon appointment)
Teacher's office