Extragalactic Astrophysics


course ID

Lecturer

CFU

6

Length

14 Weeks

Semester DD

First


Course details

1 - The Milky Way and the external galaxies, main data, classifications, catalogs. Surface photometry, luminosity function. Galactic center. Differential rotation, Oort constants. Rotation curve of the Milky Way, dark matter, WIMPs; gravitational microlensing, search for MACHOs. Disk galaxies, surface brightness, exponential profile. Observations of the gas, rotation curves, Tully-Fisher relation; sequence of disk galaxies, spiral structure, bulge, starburst, nuclear cluster, central black hole. Elliptical galaxies, photometry, shape of the isophotes, stellar velocities, Faber-Jackson relation, fundamental plane; tensor Virial Theorem, rotation in the elliptical galaxies; spectrum and stellar populations, gas, dark matter.
2 - Active Galactic Nuclei, discovery of Seyfert galaxies and quasars, radio surveys. SED; radio properties; variability, UV excess, broad lines, redshift. Radio-quiet quasars; AGN taxonomy; Seyfert 1 and 2; composite quasar spectrum; LINERs; blazars, unified schemes; Narrow Line Seyfert 1 galaxies; Broad Absorption Line Quasars; Seyfert-quasar connection; BH paradigm, Eddington limit, accretion luminosity, angular momentum; optical/UV continuum, accretion disk, Big Blue Bump; tidal disruptions; UV/optical variability; structure function, power spectral density. X-ray/UV ratio; X-ray emission, X-ray spectral components, X-ray variability; gamma-ray emission, IR, radio; superluminal motion, relativistic boosting, blazar continuum.
3 - Broad Line Region; broad lines, FWHM and line dispersion; temperature and density in the BLR; luminosity of the emission lines, filling factor; mass of the BLR, covering factor, ionization parameter, BLR stratification; emission lines profiles; cloud properties. Reverberation mapping; estimate of the black hole mass; virial theorem with external force; size-luminosity relation, single epoch mass measurement. line-continuum correlations, Baldwin effect; Narrow Line Region, line luminosities, density of the NLR gas; cloud properties; mass of the NLR; size-luminosity relation.
4 - Summary of cosmological formulae, Mattig formula; luminosity distance. Look-back time; quasar surveys; source counts, euclidean case; Eddington effect; K-correction; survey difficulties and problems. Color selection; COMBO-17 survey; effect of the emission lines; slitless spectroscopy; variability selection, synergic variability surveys; quasar surface density; V/Vmax test; luminosity function and its evolution; cosmic downsizing. Black Hole-galaxy relations. fossil BHs and Soltan argument. Quasar-galaxy coevolution. Black hole growth by accretion and merging.
5 - Intergalactic absorption lines, Ly-alpha forest, proximity effect. High redshift galaxies, angular diameter and surface brightness; K-correction, active and passive evolution; bimodality, color-stellar mass diagram, blue cloud, red sequence, green valley.

Objectives

LEARNING OUTCOMES:
Fundamental knowledge on the structure of galaxies and Active Galactic Nuclei, on their properties as sources of electromagnetic radiation, on the selection of statistically significant samples, and on the evolution of the sources in a cosmological framework.

KNOWLEDGE AND UNDERSTANDING:
- Detailed knowledge of the structure of galaxies and active galactic nuclei, of their properties as sources of electromagnetic radiation, and of their cosmic evolution.
- Knowledge of the main crietria for the selection of statistically significant samples.
- Fair knowledge of the state of the art about galaxies and active galactic nuclei.

APPLYING KNOWLEDGE AND UNDERSTANDING:
- To be able to estimate main physical quantities characteristic of galaxies and active galactic nuclei on the basis of observational data.
- To be able to read and understand recent scientific articles about the physics of extragalactic sources