I have been working on addressing the referee's comments for our DLSCL J0916.2+2951 paper. One item that was crossed off the to do list was making a redshift histogram to show if there are any line-of-sight structures that may confuse our results.
The black histogram is our sample of spectroscopic redshifts (0.1<z<1.0) in the area of our cluster. The over-plotted red histogram is the subsample of galaxies that satisfy the photo-z cut 0.43<z<0.63, which we use to select likely cluster members. We want the red histogram to completely cover the black histogram at the cluster redshift of z=0.53 but not cover the black histogram at any other redshifts. Unfortunately this is not the case, otherwise photometric redshifts would be just as good as spectroscopic redshifts.
The good news is that there is not much structure along the line-of-sight. There is a small peak at z~0.6, and worse we include a lot of these galaxies in our photo-z cut. While it is a much smaller concentration than our cluster galaxies it is worth investigating. Looking at the projected distribution of these galaxies they are very evenly distributed across the area of the cluster and there is no apparent structure to these galaxies. Thus it should not affect our results in any significant way. It is curious though, I wonder if it is a wall?
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