Monday, June 1, 2009

Plots Galore!

So, much has been accomplished since last Friday!

I made a couple of data structures (with instruction from Beth) to combine the catalogs of the different bands. So now, instead of reading in a bunch of files to make plots, etc, I just have to access either the North or South catalog I made. Sweet.

Next, continued to go through literature searching for the answer to the star-galaxy classification mystery. Finally I found a "SExtractor for Dummies" guide, and after a bit of searching found a section that said that the continuous scale rated objects from 0 (galaxy) to 1 (star).

Starting out:
Goals for the day:
Re-plot the ra-dec from the new catalog.
Plot fwhm against the classification.
Use this to approximate a cut off as to what we'll call a galaxy or star.
Also look at range of fwhm and use this to get an idea of what aperture size to use from the magnitude data.

As of lunch time:
All plots in the goals section have been made! RA vs Dec in both north and south, as well as all 8 fwhm-class plots in each band, N and S.
Proceeding to check out galaxy cut-off values as well as fluxes.

1 comment:

  1. I'm really happy with how quickly you've become adept at using IDL to manipulate data and read figures. After learning the tools during the first 2 weeks, you're already off and running with the science.

    I recommend you take a look at

    They studied stars in the Hubble Ultra Deep field. Take a look at how they separated out stars from unresolved galaxies. Then given the area of the HUDF, calculate the number of stars per area that they found. Then use this to roughly estimate the number of stars you expect to be in the GOODS area.