How galaxies and the structure of the Universe forms is one of the most fundamental questions in extra-galactic astronomy. It is also an area that has seen tremendous progress over the last 30 years, but at the same time it has constantly been challenged by ever-improving observational data. This course will introduce you to this fascinating subject and introduce you to the physics of the formation of the largest structures in the Universe.
The course will cover the growth of structure in the Universe and how the large-scale structure and galaxies form. Topics that will be covered include: the physics of linear growth and non-linear collapse, clustering and biasing, angular momentum and its influence on galaxy formation, cooling, star formation and feedback processes, the intergalactic medium and the formation of the first structures. The course will also present recent results and controversies in the field.
The course will start with a brief refresher on cosmology but it is expected that the student has had exposure to cosmology, in particular the course builds on the autumn 2013 MSc cosmology course. Problem classes will be given and considered an integral part of the course.
The evaluation of the course will be done based on the exam plus up to 25% from the homework problem sets.
There will be two sets of homework given during the course. Handing in these exercises is obligatory. They will be graded and will count for up to 25% of the final grade if they would improve your grade. In other words, the homework cannot hurt your exam grade but they can help it.
There will be a set of short problems associated to each lecture. These form the focus of the problem class and will be done and discussed there.
This is an outline of what I expect to cover in each lecture. This should not be taken as a promise that I will be able to do so! After the first few lectures, I will be providing a short 1 page summary of the coming lecture which I will expect you to have read by the time of the lecture. The idea with this is to be able to discuss the lecture content a bit more freely.
Follow the lecture title link to get to a page with the lecture notes and further background information (when they become available!).
This lecture will give a background to the course and a brief recap of cosmology and some essential physics through an exploration of why galaxies have the mass they seem to have.
We will review the growth of perturbations,
We look at Silk damping, free streaming and how dark matter influences the growth of baryonic perturbations. We introduce the concept of the power spectrum and give a brief overview of Baryon Acoustic Oscillations.
Window functions and non-linear scaling laws and the time/mass of collapse. Finally we cover the spherical collapse model briefly.
The Press-Schechter mass function.
Extended Press-Schechter and the formation time of dark matter halos.
Uses of the extended Press-Schechter relation and virial relations.
Hydrostatic equilibrium and Jeans mass. Time-scales of collapse and cooling processes.
Cooling, effect of metals and of heating. The cooling flow problem in galaxy clusters.
The cooling radius and hot and cold accretion. The spin parameter.
The formation of disk galaxies.
Formation of realistic spiral galaxies, adiabatic contraction, accretion, star formation, stability and feedback.
Absorption by the IGM. Gunn-Peterson throughs. Observations + theory. Epoch of re-ionization.
Re-ionization. Strömgren spheres in expanding Universe/clumping factors and emissivity.
I use the recent book "Galaxy formation and Evolution", Hojun Mo, Frank van den Bosch & Simon White (ISBN 978-0-521-85793-2) as reference for part of the course, but that book covers more material than we are able to cover in one semester. The main chapters are 5-9, 11, 12, 15-16. It is not necessary to buy this book, but if you plan to do a project in this field it is a good investment.
Books that are useful for the course include:
It is useful to explore various videos of galaxy formation simulations to get a feel for what is happening - and they are of course quite nice to look at: