Astr 498V Fall 2001
Galaxies Sylvain Veilleux
September 11, 2001 DUE: September 18, 2001
Estimate the average density of the Local Group of galaxies and compare it with the critical density g cm-3. What are the implications of your result? Mention the references you use for your calculations.
The time taken for a galaxy or cluster to grow to density must be at least as great as the free-fall time (G = gravitational constant), since cosmic expansion must first be halted locally. What is tff for (a) the Milky Way () and (b) a cluster of galaxies (). Compare with the Hubble time H-10.
We saw in class that the power spectrum
Linder's ``? Think About 1.3'' on p. 16
Linder's ``? Think About 1.4'' on p. 17