Prerequisites
It is assumed that students are familiar with the basics of the Part II course
Astrophysical Fluids and with the basics of the Part III Cosmology course (Michealmas term).
Learning Outcomes and Assessment
The course will discuss how structure forms in the Universe on all scales from stars, through galaxies,
to the largest structures we know about in the Universe. At the end of the course students will be familiar
with the main models of star formation and of galaxy evolution throughout the cosmic epoch,
as well as with the several observational results that have been obtained so far, validating or testing these models.
The topics covered are at the forefront of active research in astrophysics. Failings of our current understanding and models will be discussed along with likely developments in the near future, which will be achieved thanks to the advent of new major observing facilities and new advanced numerical simulations.
Synopsis
Introduction: overview of the evolution of structure in the universe; main properties of galaxies in the local universe; star-forming regions; a first-look at the high-redshift universe.
Physical processes in the baryonic gas: heating processes; cooling processes; emission mechanisms; thermal stability and instability; multi-phase medium in galaxies; baryonic gas in the early universe.
Gravitational stability and instability: the isothermal sphere as a simple model; virial equilibrium; Jeans analysis in an infinite medium; role of magnetic fields, turbulence and angular momentum.
Formation of stars: inside-out collapse; formation of the first core and second core; deuterium burning; hydrogen burning; angular-momentum, discs and stellar jets.
Star-formation on galactic scales: properties and structure of star-forming galaxies; initial mass functions; factors controlling star formation; Schmidt-Kennicutt star-formation law; starburst galaxies; a first look at star formation histories.
Cosmological origins of structure: Origin and early growth of density perturbations and the matter power spectrum.
Galaxy formation: collapse of a spherical over density; evolution of the baryonic gas; numerical simulations;
hierarchical structure formation; galaxy dynanmics.
Supermassive Black Holes: observational evidence; measurement of black holes masses;
black hole scaling relations; black hole accretion; Active Galactic Nuclei (AGNs).
Feedback in galaxies: the need for negative feedback; supernova feedback; AGN feedback;
improved models for galaxy evolution; positive feedback.
The high-redshift universe and galaxy evolution: observational properties of galaxies at high redshift;
evolution of the galaxy population; dominant galaxy evolutionary mechanisms; evolution of the AGN population and evolution of black holes; confronting predictions and observations; formation of the first stars and of the first black holes in the primordial Universe.
Large-scale structure: clusters and superclusters; correlation functions; remnants of primordial structure; the cosmic web.
Challenges: problems with our current models of galaxy formation; the end of the dark ages – the epoch of re-ionisation; the equation of state of dark energy; testing our predictions.
BOOKS
The physics of the interstellar medium, Dyson J E and Williams D A (2nd edition IoP)
Accretion processes in star formation, Hartmann L (Cambridge)
An introduction to modern cosmology, Liddle A (2nd edition Wiley) – a good and relatively simple text to put material in context
The Structure & Evolution of Galaxies, Philips S (Wiley)
Galaxy formation, Longair M S (2nd edition Springer)
Cosmology – the origin and evolution of cosmic structure, Coles P and Lucchin F (2nd edition Wiley) – a more advanced text
Observational Cosmology, Sarjeant S. (Cambridge)