AY 101-002                                                        Spring 2008
                                 QUIZ #10

Answer each of the following on a computer-gradeable answer sheet. Be
sure to fill in your name and student number (and blacken their circles as 
well). Write your seat number on a corner of the answer sheet.

1. Many elliptical galaxies likely originated
   a) from the gradual formation of stars over all of cosmic time.
   b) when irregular galaxies exhausted the gas available for starbirth.
   c) from gas swirling around central massive black holes.
   D) WHEN COLLIDING SPIRAL GALAXIES MERGED. 

2.  We can estimate the age of our Universe by
   A) MEASURING ITS PRESENT EXPANSION RATE.
   b) measuring the ages of Population I star clusters from their HR diagrams.
   c) finding the minimum fraction of helium in intergalactic gas.
   d) finding out how rapidly the expansion is slowing down.

3. Over cosmic time, the number of quasars
   a) has stayed roughly constant.
   B) INCREASED RAPIDLY AND HAS DECLINED FOR MOST OF COSMIC HISTORY.
   c) has increased to today's value.
   d) has continuously decreased.

4. In addition to the galaxies, clusters of galaxies contain
   a) swarms of intergalactic black holes, detected as X-ray sources.
   b) clouds of cold intergalactic hydrogen.
   C) LARGE MASSES OF HOT, X-RAY EMITTING GAS.
   d) significant amounts of intergalactic dust.

5. "The Universe looks the same on large scales to everyone" states the
   a) steady-state cosmology.           C) COSMOLOGICAL PRINCIPLE.
   b) Hubble law.                       d) Big-Bang scenario.

6. The sky gets dark at night, and this tell us that
   a) the Universe contains a great deal of light-absorbing material.
   b) the Universe must be infinite in extent.
   c) the Universe must be infinitely old.
   D) THE UNIVERSE CANNOT BE BOTH INFINITELY LARGE AND INFINITELY OLD.

7. From study of galaxy clusters at various distances, we find that
   a) rich clusters have always contained a similar mix of elliptical galaxies.
   B) RICH CLUSTERS ONCE INCLUDED MANY MORE SPIRALS THAN TODAY.
   c) clusters are slowly losing galaxies as they escape the cluster gravity.
   d) clusters are the major locations of starbirth in today's Universe.

8. The center of the cosmic expansion
   a) must be close to the Milky Way, for us to see Hubble's law so clearly.
   B) IS EVERYWHERE, WITH EQUAL ACCURACY.
   c) must lie beyond the range of our telescopes.
   d) is marked by the huge Coma cluster of galaxies.

9. Tracing the cosmic expansion rate backward in time gives an age of most nearly
   a) 1.5 million years.                c) 1.5 billion years.
   b) 150 million years.                D) 15 BILLION YEARS.

10. The Big Bang picture in cosmology describes
   a) a vast explosion sending matter flying through space from its origin point.
   B) AN EXPANSION OF SPACE ITSELF, OCCURRING EVERYWHERE.
   c) explosions which produced the matter in each individual galaxy.
   d) the role of supernovae in the history of cosmic matter.