Extragalactic Astronomy -
Fall 2012
Homework #8 - due November 5
1. When was the first galaxy survey that extended deep enough to see a
homogeneous universe?
2. Describe in words the physical interpretation of the parameter
usually used to specify the normalization of the matter density power
spectrum.
3. Explain the shape parameter in terms of the evolution of density
fluctuations during the early (< 1 Myr) history of the universe.
4. Do density fluctuations in baryonic matter evolve in the same way as
density fluctuations in dark matter? Explain.
5. Which is larger, the bias factor for galaxies or clsuters?
6. What causes a type Ia supernova?
7. Why are gray dust and cosmological evolution of SN Ia ruled out as
causes of the distance versus redshift evolution found for type Ia
supernovae?
8. In a highly ionized medium, how does the density of HI depend on the
density of protons?
9. At about what multipole is the first peak in the CMB power spectrum?
10. When was the universe reionized?