Friday, November 20, 2009

Mock Reconstruction

I ran a full reconstruction on the mock data over the past couple days. There are some problems with this run (which I discovered after I started it running, but decided to just let it finish). The first is that I have not fixed the distribution of the randoms in the 2D correlation function to go as cosine for the declinations (they are flat). The second is that I discovered the mock catalog I was using was not dark matter halos but actually LRGs and to the clustering properties are nonsensical. I have since gotten a dark matter halo catalog from Martin White.

Here are the 2D and 3D correlation function for the various redshift bins:

2D correlation functions for redshift bins

3D correlation functions for redshift bins

As you can see the 3D correlation function are no longer fluctuating around zero as they were on the Sloan data.

The reconstruction is a bit puzzling. Below is a histogram of the comoving distances (from the center of the sphere) of the spectroscopic (yellow), photometric (green) data sets as well as the reconstructed phi (redshift distribution (pink)). You will noticed that while the histograms don't match, the bumps in the photometric/spectroscopic histograms seem to match the bumps in phi. I was thinking that because these photometric/spectroscopic histograms include both the geometry and the "selection function" so to speak (I didn't actually apply a selection function, so it is just the natural clustering of the objects). Whereas phi (I think) is only supposed to be the selection function, not the geometry. I was wondering if perhaps if I subtract the geometry from the p/s histograms (which is proportional to r^2) then we would basically be left with these same wiggles? I've asked Alexia about this and I am waiting for a response.

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