Introduction
You have two weeks to complete this unit. Below I give a syllabus for the unit, together with guidance as to where you can find the relevant material. More detailed advice on how to approach the work is given in the introduction to Unit 1 , and will not be repeated here. This unit contains less material than the others, but you will need to familiarise yourself with using the various formulae involved, and to think carefully about what they mean, in order to get a good grasp of them. You should aim to spend about 12 hours on the unit, and take the self-test problems very seriously.
Syllabus and source
In this final unit, we make the connection between theory and observation. This involves the relationship between abstract parameters like comoving coordinates, and things we can observe, like redshift, flux, and size. You will find that Liddle (in his Advanced Topics) and Rowan-Robinson contain much of what you need. As usual, Liddle is clearer, whilst Rowan-Robinson gives more observation-related material. You may also find this paper by David Hogg very useful to learn about distance measures in cosmology.
Finally, I suggest rounding the course off by reading the interesting and perceptive esssay by
the Astronomer Royal, Sir Martin Rees. This is mostly about cosmology, and will give you the "big picture". You should
find that you can understand it a lot better than would have been the case three months ago. Take it home for
Christmas!
| Topic | Sources | Comments |
| Relationship between redshift & distance Light rays and the R-W metric Role of curvature and of H(z) Low z approximation |
L2, L3(A2.1) and Unit 5 lecture | Note that rigorous solutions for r(z) in general cosmologies normally have to be calculated numerically. |
| Flux & luminosity distance Surface area of a sphere Effect of redshift on flux Definition of DL Application to high z SNe |
Unit 5 lecture, RR(7.2,7.6) L2, L3(A2.3) |
Note that RR defines P to be the luminosity radiated into unit solid angle - i.e. P=L/(4.pi). |
| Angular size & angular-diameter distance Definition of DA Behaviour of angular size with redshift |
RR(7.8) L2, L3(A2.4) Unit 5 lecture |
Remember that RR uses Z=1+z. |
| Magnitude-redshift relation & K-correction | RR(7.7) | |
| Space density and number counts Volume element vs redshift Number counts for a non-evolving population Effects of source evolution on number counts |
RR(7.9, 3.5) L2, L3(A2.5) |
|
| Piecing it all together |
Rees paper | Read this interesting essay on our understanding of the
Universe by Martin Rees, for a perspective on where cosmology has now
brought us. |
Notes
- Key: RR=Rowan-Robinson, L2=Liddle, 2nd edition , L3 - Liddle, 3rd Edition - relevant sections are given in brackets.
- The topics listed are not of equal size.
Unit 5: Observational properties and cosmological tests
Introduction
Syllabus and sources
Self-test problems
Units
- The Hot Big Bang
- Cosmological theory
- Evolution from the Big Bang
- Dark matter & baryons
- Observational properties and cosmological tests
Contact
Email:
Office: Physics West, 223