Sarah's Spring 2008 page
- What is your project? Why is it important to measure redshift-independent
distances?
- What are "peculiar velocities"? What cause them? How big are they?
- What methods are used to derive redshift-independent distances to nearby
galaxies? Try to understand and write a summary on each of these
methods:
- Cepheid variable stars
- Tip of the red giant branch
- Brightest stars
- Planetary nebulae
- Surface brightness fluctuations
- Type Ia supernovae
- Why aren't supernovae very helpful in the local volume?
- See the (out of date!) documentation on the EGG
distance calibrator catalog. (One of your jobs will be to
update the catalog and its documentation!)
- Make copies of these files for yourself in your own directory.
- Write an IDL program to read the data file "dist_calibs.dat"
into an IDL structure.
- Make a plot of the distribution of galaxies on the sky.
Make a web page for yourself to keep track of what you are doing; you should
put it in the directory called /home/hatillo/tyree/spr08. See
my hints on how to get started.
Numerical integration of an HI profile
- Use our links to find the ALFALFA data entry for AGC/UGC 7192. Put the
link on your webpage.
- On your webpage, record for yourself the ALFALFA catalog information
for this object. Do you understand what the parameters mean? Add notes
for your own reference, as needed. If possible,
enter the data as a table on your webpage; if you don't know how to do
it, ask for a hint.
- Make a link on your web page to the journal article containing the
ALFALFA publication of this spectrum.
- Download the spectrum (ASCII file format) to your disk area on hatillo.
- Write an IDL routine to calculate the integral under the profile.
If you run into "issues", ask! This will probably take you some
time as you need to know how to read in a file, among other things.
Assignment for next few weeks (Progress report due Mar 24; 2nd report due Apr 14):
- Read the paper by
Mei et al.(2007) on SBF fluctuations in the Virgo cluster.
- Add the objects from that paper to the distance calibrator database.
- Read the section from Karen's thesis on flow models (ask Martha for a copy).
- Learn to use the IDL_ALFA flow model routines.
To access Sarah's progress page,
type "file:///home/hatillo/tyree/idl/progress.htm" into your browser and you will get it.
Last modified: Sun Mar 9 21:23:43 EDT 2008 by martha