COURSE CREDIT FOR FUN AND PROFIT


Ay 124:  Gilmore's Projects
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At the end of the GKK, there is a chapter with "some interesting and 
tractable problems".  These are basically good, ambitious thesis topics.  
However, you may contemplate treating them as review subjects: research 
a topic which strikes your fancy, and write a mini-review about it -- or
a synopsis of what would it take do get the problem solved.  Who knows, 
you may end up doing it some day.  Some may even bear a partial research
solution, or suggest a small, subsidiary research project.  Doing this 
would liberate you from a certain number of homeworks, depending on the 
scope of your project.  Look at them, think about it, and come talk with 
me about the possibilities.  Team work in groups of two is acceptable.



Ay 124:  Small Research Projects
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This is another way to earn the course credit, while at the same time 
learning the research skills, and learning about and around the topic in 
question.  People who do a research project will be freed from writing a
suitable number of reading reports (the exact number depending on the 
project, performance, etc.)  The projects can be done individually, or
in teams of two people, with some guidance from, and interaction with me.
Hopefully, the work may even lead to a publishable paper.  For example, 
a project done by Will Deich in Ay 124 last year provided a tentative 
evidence for a bar in our Galaxy, and will be published in a real journal.

Here are some ideas, but the list will grow.  Try also to think of some 
of your own:

1. How high above the Galactic plane is the Sun?

   There is an observed asymmetry in the IRAS source counts, which 
   suggests that the Sun is above the physical disk plane. (This was 
   already known from the optical data.)  The z-height value is maybe 
   10 - 20 pc.  Here one would model the IRAS source counts, and try 
   to determine the z-height from them. 

2. Far-IR properties of globular clusters

   Some, but not all Galactic globular clusters have been detected by 
   IRAS (i.e., they are in the catalogs).  Two things should be done: 
   (1) examine the actual IRAS flux images to see what they look like, 
   and (2) examine critically the catalog associations, and analyse the 
   properties of the genuinely detected clusters.  The ultimate goal 
   (which is outside the immediate scope of this project, but you are 
   welcome to it) is to search the IRAS data base for the previously 
   unknown, obscured globular clusters. 

   A related, shorter project would be to examine the IRAS properties 
   of the Magellanic Clouds' star clusters.

3. UV properties of globular clusters

   Here one would use the UV spectra obtained by the IUE satellite, and 
   combine them with the optical data.  The goal is to see if the clusters 
   with post-collapse cores have anomalously UV-bright cores (due, e.g., 
   to a centrally concentrated population of binaries, blue stragglers, 
   or some other strange beasts).  This expands on the work on color and 
   population gradients in cluster cores done in the optical, which is 
   rapidly becoming one of the hottest topics in globular cluster research.

4. History of the star formation in the universe

   Distribution of colors of galaxies shows that there are two basic
   "populations":  (1) ellipticals/bulges, whose red colors show a very 
   narrow distribution, suggesting an old age and a short time interval 
   for their formation; and (2) disks, whose colors span a wide range, 
   suggesting a gradual formation, spread over most of the Hubble time.  
   In principle (but difficult in practice), these color distributions 
   can be inverted, using galaxy population synthesis models, to map the 
   history of the star formation in the universe.  The first task is to 
   compile a volume-limited, luminosity-weighted catalog of galaxy colors
   (we have the necessary catalogs on the computer), and then use the
   program which generates the (Bruzual) population synthesis models,
   and try to convert the colors into ages.

I will probably think of more as the term progresses.  Please see me if 
you want to discuss any of these, or any other ideas of your own.