Ay 154, Winter 1989:   Take-Home Final Exam
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The main purpose of this exam is to give you some practice for the 
Candidacy Exam.  ("It's good for you...")  However, the quality of
your performance here can affect your course grade.

Answer the minimum of 6 questions, from the list below.  You can do
more, of course.  Try to answer the questions on your own, as well as 
you can.  If you get stuck, have a peak at your notes, the books, or 
whatever.  You will not be graded so much on the "correctness" of the 
answers, but rather on the basis of the effort shown, and the ability 
to think independently and make reasonable intuitive guesses.  Use about 
0.5 - 1 page per question: be concise, and give the essential points.

The answers are due in my office by midnight of the St. Patrick's Day 
(Friday, March 17).  

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1.  What can we say about the formation of our Galaxy, from the evidence
    from stellar populations?  Describe the ELBS picture, and the more
    modern developments.

2.  What are the basic equations, theorems, etc., of stellar dynamics?
    What are the important time scales?  Describe briefly the King-type 
    models.

3.  Which dynamical processes are important for the evolution of the disk,
    open clusters, globular clusters?  Give numerical estimates of the
    relevant quantities.

4.  Discuss the luminosity and mass functions of stars, how are they 
    measured, what are the problems, etc.

5.  Where does the spiral structure come from?  Why does it persist?

6.  Do a quick, back-of-the-envelope estimate of the kinetic and potential
    energy of our Galaxy, and its mass.  You can assume a flat rotation
    curve, and a cutoff at 30 or 50 kpc.  Then do the same for an average
    elliptical galaxy.  Estimate the free-fall times.  If the binding
    energy is released during a single free-fall time, what luminosity
    would that give to a protogalaxy?  Can you guess the wavelength region
    in which the energy will be predominantly released (give reasons)?

7.  Which physical and observed properties provide the best descriptors
    for elliptical galaxies?  For spirals?  What does it all mean, and
    what can it be used for?

8.  Discuss the dependence of galaxian properties on the environment.

9.  What can be learned from the x-ray gas in ellipticals and clusters
    of galaxies?

10. How do we describe and study (both qualitatively and quantitatively)
    the large-scale structure?  What are the important outstanding problems?

11. Invent your own question of the caliber similar to those above.