Unformatted text preview: ? 4. Do parts (a), (b) and (c) of problem 2.11. Without doing part (d), do you think the observable stars able in regions B and C would be more or less metal rich than what is actually in your model sky? 5. Consider hydrogen gas in the galactic plane. Assume the Sun is at a distance of R = 8 kpc from the Galactic center with the average Galactic rotational velocity at that distance of V = 200 km/s. Also assume that V ( R ) is con-stant. Suppose there are 2 uniform rings of gas in the Galactic plane, one at 4 kpc radius and the other at 12 kpc radius, with negligible height and width compared to their radii. Derive an expression for the radial velocity of these rings as a function of Galactic longitude ‘ . Also derive an expression for the observed intensity of each ring as a function of ‘ ....
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- Spring '11
- Galaxies, #, 0.1 m, galactic center, 200 km, 100m