Tuesday, February 2, 2010

1M Reconstruction

I ran a big reconstruction on the CAS data using 1,000,000 objects, and 20 redshift bins. The correlation functions at the lower redshifts (less than 720 Mpc/h) have much less noise:


But the correlation functions at larger redshifts look pretty noisy:


Perhaps I should bin so that I have a constant number of objects per bin instead of by equal redshift bins.

When I do the reconstruction, I get puzzling results:


The reconstruction seems to think there are a large number of points at redshift > 1.0 which aren't there. This could be due to low statistics at these redshifts and so the reconstruction just isn't working properly. The number of spectroscopic objects per bin is as follows:

0-120 Mpc/h: 14597 galaxies in spectroscopic dataset
120-240 Mpc/h: 45954 galaxies in spectroscopic dataset
240-360 Mpc/h: 55489 galaxies in spectroscopic dataset
360-480 Mpc/h: 59451 galaxies in spectroscopic dataset
480-600 Mpc/h: 64381 galaxies in spectroscopic dataset
600-720 Mpc/h: 56290 galaxies in spectroscopic dataset
720-840 Mpc/h: 55916 galaxies in spectroscopic dataset
840-960 Mpc/h: 49536 galaxies in spectroscopic dataset
960-1080 Mpc/h: 29109 galaxies in spectroscopic dataset
1080-1200 Mpc/h: 20852 galaxies in spectroscopic dataset
1200-1320 Mpc/h: 16729 galaxies in spectroscopic dataset
1320-1440 Mpc/h: 13715 galaxies in spectroscopic dataset
1440-1560 Mpc/h: 8969 galaxies in spectroscopic dataset
1560-1680 Mpc/h: 5094 galaxies in spectroscopic dataset
1680-1800 Mpc/h: 2374 galaxies in spectroscopic dataset
1800-1920 Mpc/h: 890 galaxies in spectroscopic dataset
1920-2040 Mpc/h: 381 galaxies in spectroscopic dataset
2040-2160 Mpc/h: 169 galaxies in spectroscopic dataset
2160-2280 Mpc/h: 85 galaxies in spectroscopic dataset
2280-2400 Mpc/h: 16 galaxies in spectroscopic dataset

It looks like I shouldn't use bins greater than ~1Mpc/h for the reconstruction because we have so few galaxies out there. If I try doing the reconstruction only using bins up to 1080 Mpc/h this is that I get:

There seems to be a problem at the earlier redshifts, perhaps due to low statistics in the first redshift bin? But the reconstruction looks sort of good.

I'm need to see what Alexia thinks about this "forcing to zero" issue at the edges. I also want to try this with the LRG catalog. I'm going to set a run going where I bin such that there are constant numbers of galaxies per bin, not constant redshifts. Alexia, let's chat tomorrow early?

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