April 12, 2019
April Updates
Status of the Project
Alex and I have settled on an ideal way to deal with the photometric redshift uncertainties on the RedMaPPer (RM) cluster data. The plan is to divide everything into fairly small redshift slices, corresponding to around 30 Mpc. For each slice, I'll make a projected number density map with the CMASS galaxies. (They have very low redshift uncertainties so they are essentially guaranteed to truly exist in that slice.) For every RM cluster, the catalog provides not only the calculated mean photo-z but also the probability distribution of photo-z. Therefore, for each redshift slice, I'll take every RedMaPPer cluster that has any probability of being in that slice (including those whose mean photo-z falls in another slice), and run these through COOP to get the orientation vector for each cluster. For example, if a cluster's photo-z probability extends over the z=.2 to .21 slice, the z=.21 to .22 slice, and the z=.22 to .23 slice, I will run this cluster with the orientation map for each of those bins and get 3 orientations out. Finally, I'll write my own stacking code which, for a single redshift slice of 30Mpc, stacks all the clusters that could possibly exist somewhere in that slice, orients them with the imported COOP orientations, and weights each cluster by the probability that it exists in that slice. (That probability is the area under the photo-z curve within that slice). With this method, we can do oriented stacks for reasonably small redshift slices and fully account for the uncertainties in the photometric redshifts of clusters.
However, re-writing and re-organizing my code to do this will be a long enough task that I won't be able to do it by the end of 1501. For the rest of the 1501 time period, I'll simply take slices of 100 comoving Mpc, make number density maps with all the CMASS galaxies in those slices, and assume that the RM clusters' photo-zs are accurate.
The CMASS sample is chosen to have mostly constant mass. The stellar mass is shown in this figure, taken from ___. According to this paper ___, the halo mass is related to the stellar mass by ___. I am matching the
Numbers
I want to put these numbers all down in one place so they're easy to find for future reference. For 100 Mpc slices, the amount of DES Redmapper clusters in each slice which overlap within the ACT region (and are at a sufficient distance from the edge of the ACT map) are:
432 to 532 Mpc: z = 0.100 to 0.124, 230 clusters,
532 to 632 Mpc: z = 0.124 to 0.148, 199 clusters,
632 to 732 Mpc: z = 0.148 to 0.173, 300 clusters,
732 to 832 Mpc: z = 0.173 to 0.197, 320 clusters,
832 to 932 Mpc: z = 0.197 to 0.222, 488 clusters,
932 to 1032 Mpc: z = 0.222 to 0.248, 702 clusters,
1032 to 1132 Mpc: z = 0.248 to 0.274, 725 clusters,
1132 to 1232 Mpc: z = 0.274 to 0.300, 781 clusters,
1232 to 1332 Mpc: z = 0.300 to 0.327, 726 clusters,
1332 to 1432 Mpc: z = 0.327 to 0.354, 750
1432 to 1532 Mpc: z = 0.354 to 0.381, 1062
1532 to 1632 Mpc: z = 0.381 to 0.409, 1058
1632 to 1732 Mpc: z = 0.409 to 0.438, 1295
1732 to 1832 Mpc: z = 0.438 to 0.467, 1327
1832 to 1932 Mpc: z = 0.467 to 0.496, 1541
1932 to 2032 Mpc: z = 0.496 to 0.526, 1548
2032 to 2132 Mpc: z = 0.526 to 0.556, 1714
2132 to 2232 Mpc: z = 0.556 to 0.588, 2136
2232 to 2332 Mpc: z = 0.588 to 0.619, 1958
2332 to 2432 Mpc: z = 0.619 to 0.652, 1314
2432 to 2532 Mpc: z = 0.652 to 0.684, 478
2532 to 2632 Mpc: z = 0.684 to 0.718, 115
2632 to 2732 Mpc: z = 0.718 to 0.752, 28
2732 to 2832 Mpc: z = 0.752 to 0.787, 2
In the same redshift slices, these are the numbers of CMASS galaxies in the catalog I'm using:
Example Plots of CMASS Sample
When I divide the DES Redmapper sample into slices of 100Mpc each, the