27218 - Extragalactic Astrophysics

Learning outcomes

Working knowledge (qualitative and quantitative) of extragalactic astrophysics. Subjects cover the structure, dynamics, formation and evolution of  galaxies and their gaseous and dark matter components. Special attention is dedicated to central supermassive black holes, accretion theory and AGN physics. Some information about modern cosmology is also provided. The student will be able to understand research papers on extragalactic astrophysics.

Course contents

OBSERVATIONAL-MORPHOLOGICAL SECTION: General properties of stellar systems, from galactic to cluster scales; luminosity profiles, colors and stellar populations; kinematical properties:velocity dispersion, rotational velocity, ellipticity; Mbh-sigma, Lx-Lb, Faber-Jackson, Kormendy, Fundamental Plane, Tully-Fisher relations. Introduction to observational Cosmology.

THEORY (part 1): Basics of Stellar Dynamics: slingshot effect, collisionality and two-body relaxation time in impulsive approximation, dynamical friction, virial theorem, phase-space distribution functions, Jeans equations.Gravitational evaporation, gravothermal catastrophe and gravothermal oscillations. Dynamical evolution of open and globular clusters. [this part can be considered an introduction to the course of Dynamics of Stellar Systems]

THEORY (part 2): Elements of astrophysical fluido dynamics (material derivative, transport theorems, continuity, momentum and energy equations, viscosity and thermodynamics, Kelvin, Bernoulli, Poincare' theorems, barotropic and baroclinic equilibria, rotating flows, dispersion relations, sound velocity). Basics of accretion phenomena, Bondi accretion, Eddington luminosity, Jeans instability. Galaxy formation: monolithic, dissipationless and dissipative galaxy formation. Relations between QSO activity and galaxy formation. Cooling flows.

THEORY (part 3): introduction to modern Cosmology.

Readings/Bibliography

'Dynamics of galaxies' (G. Bertin, Cambridge University Press) 'Galactic Dynamics' (J. Binney, S. Tremaine Princeton University Press) 'Galactic Astronomy' (J. Binney, M. Merrifield Princeton University Press) 'Dynamical evolution of globular clusters' (L. Spitzer Princeton University Press) 'Lecture notes on stellar dynamics' (L. Ciotti Scuola Normale Superiore Pisa). 'Introduction to Cosmology (B. Ryden, Addison Wesley).

Teaching methods

Class lectures with illustrative exercises. Discussion of the most relevant research papers published on international journals.

Assessment methods

Final oral examination. The examination is 45 minutes long, at the blackboard, organized in 3 sections (each 15 minutes long). In the first part the student illustrates a selected subject (the aim is to verify the presentation abilities of a well studied argument). In the second part the student is asked to solve a simple exercise (test of numerical abilities, and of a back-to-the-envelope estimate). In the third and last part a random argument from the program is discussed (test of the global preparation).

Teaching tools

Lecture notes, selected chapters from technical books, selected research papers.

Office hours

See the website of Luca Ciotti

See the website of Silvia Pellegrini