Thursday, February 24, 2011

Figuring out Mask Problems

I re-made the random catalogs without removing the duplicates. David thought that perhaps this was causing problems with the randoms not matching the catalogs or the correlation functions not working properly.

Below are a bunch of histograms of the distribution of the data (white) and randoms (green) for the two methods I have tried for making randoms, mine and Shirley's. You'll notice that the spectroscopic randoms mismatch the spectroscopic data much more than the photometric data/randoms (for both methods). This makes me perhaps think there is a problem with the mask I am using for the spectroscopic set. Martin White made this mask for me.. I've ask for a meeting with David this afternoon to look at this in more detail.

My randoms

Shirley's Randoms

I've tried zooming in on regions in the data where the mismatch is greatest. For instance ( dec > 40, 110 < ra < 130). I've posted these on the blog too.

It does look like there are regions where there are data and not randoms, which would suggest a problem with the mask. (Note that the regular spacing of the randoms is because this is how Shirley generates randoms, by putting an object in the center of the grid). I plotted these because it is easier to see with the regular spacing that regions have been missed. For instance at ra ~129.4, dec ~ 49.4, There are several data points (red), but but randoms (blue). You can click on the below pictures to make them bigger.

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