Fall 2000 ASTR 1120-001 Review for Quiz 5

The quiz will contain 10 multiple-choice questions, and will be 10 minutes long. The intention is that all material on the quiz (saving matters of logic and common sense) is referred to somewhere here.

You can ask about the answers in the review session at 6-7pm on Monday 27 November in Duane G1B30 (our usual lecture hall).

  1. Milky Way. Give an account of the history of the development of our understanding of the Milky Way. How did Galileo, Herschel, Leavitt, Slipher, Shapley, Hubble, Oort and Lindblad contribute? More info here. What observation finally settled the issue of the nature of the spiral nebulae? What observations finally settled the question of where was the center of the Milky Way?

  2. Redshift. What is a redshift? Most galaxies appear redshifted. What does this imply?

  3. Cepheid Variables. What are Cepheid variables? Where are they in the HR diagram? What is the Period-Luminosity law for Cepheid variables, who discovered it, and how? Why are Cepheid variables a particularly important rung on the Cosmic Distance Ladder?

  4. Expansion of the Universe. What observation, by whom, led to the notion that the Universe is expanding? What is a Hubble diagram? What is Hubble's Law? What is thought to be the approximate value of Hubble's constant? Why is Hubble's constant of fundamental interest in cosmology?

  5. Age of the Universe. How do we measure the age of the Universe? Approximately what is the age of the Universe?

  6. Local Group. What is the Local Group of Galaxies? The Local Group is the region of the Universe that has turned around from the general Hubble expansion of the Universe, and is collapsing for the first time. About how many galaxies does it contain? About what is its radius? Who are its largest members? Does our Galaxy have companion galaxies in orbit around it? Does the Andromeda Galaxy (M31), the largest member of the Local Group, have companion galaxies in orbit around it?

  7. Local Supercluster. Describe roughly what the Local Supercluster looks like. In what constellation lies the center of the Local Supercluster? Whereabouts is the Local Group in the Local Supercluster? Is the Local Group moving towards or away from the Local Supercluster? Are there other groups in the Local Supercluster? Why does the Local Supercluster appear flattened?

  8. Rotation Curves. What is a rotation curve? What can you deduce from the rotation curve of a galaxy? In what sense are rotation curves evidence for Dark Matter? Do rotation curves tell you what the Dark Matter is made of?

  9. Galaxy Collisions. Do galaxies collide? Do stars collide? What happens to galaxies when they collide? When galaxies collide, what actually collides? How do galaxy collisions affect spiral structure?

  10. Galaxy Types. What has spiral structure got to do with star formation? What makes Irregular galaxies look patchy and, well, irregular? Galaxies such as M82 (the one that made a near passage past M81), and the Large and Small Magellanic clouds are apparently undergoing an epoch of vigorous star formation. Why is this thought to be happening? Elliptical galaxies prefer to hang out in high density regions such as the Virgo cluster. Why?

  11. Galaxy Clustering. Why do galaxies cluster? Were galaxies more or less clustered in the past? There are currently major programs underway to measure redshifts of many galaxies. What is the purpose of these programs?