Monday, July 13, 2009


I Double checked the chi and sharp cuts I made:

I ended up using:
--sharp: -0.5 to 0.5
--chi: 0.8 to 1.5
This is more or less a generous cut to clean things up a bit. More could be done to get a more stringent cut. I also remade the CMD with these cuts and without getting close to Wil1. It looks pretty good. I noticed that the isochrone wasn't doing a good job of describing the data and realized that I must have used the wrong distance to Wil1 when I calculated the distance modulus. But that's fixed and all is well. I used the same code Anna and I wrote for Segue to match stars to within 1 sigma of the M92 isochrone. I also made a Hess Diagram which I've been playing with, but also looks really good.

I also set out to tweak the contour plot of stellar density:

Like I just mentioned, I did a better job of selecting the stars for the CMD and used only the stars that matched the chi/sharp and isochrone cuts but didn't do any ra/dec cuts so that I would have the whole field to work with. I messed with Beth's annulus idea only to realize that I was already scaling the smoothed density plot. But I wasn't ignoring the central region (where Wil1 is). So I made a mask that cut out the central square before I scaled things. It was a crude way of doing it and could be changed, but I think it'll do for now. My contours definitely turned out looking a lot better so I think I'm going to tweak the smoothing and binning tonight to see if I can't get it looking really good by tomorrow.

So, in all, I now have newly updated figures from KPNO data including: hess diagram, CMD with isochrone fit, chi and sharp cuts, stellar density plot.


Max likelihood for KPNO
-still dealign with negative loglikes?
-got an email from Dave--he thinks I might have to get fancy like he did with LBT. He also pointed out some other stuff in his code that might be useful to change. I'm gonna look into this more tomorrow and probably talk to him about it.

Absolute Magnitude
Beth's been thinking a lot about how to calculate this and gave me a pretty good way of going about it. I wanted to finish what I was already working on, but this is on the plate for tomorrow.
-plots and normalization
-final calculations
-mag limit from 2006--90% completion

1 comment:

  1. 1. "get fancy like he did with LBT" - uh oh. I'm afraid to ask.

    2. I'll be in the lab this morning... want to see the spatial density plots and the code. Looking forward to it!

    3. I had a dream about cumulative stellar luminosity functions. I wish I was kidding.