The clustering of galaxies around damped absorbers
We measured the clustering of galaxies around damped absorbers, all at a redshift of approximately three. For this purpose, we used wide-field images that covered a total area of one square degree. We selected galaxies that were close to the absorbers (in a redshift slice) using Bayesian photometric redshift techniques. In the redshift slice centered on the absorbers, we detected the clustering of galaxies at the 87% confidence level. Due to the small sample of absorbers, we could not conclude whether the clustering was larger or weaker than that of the galaxies with each other. As a cross-check, in three other redshift slices that were not centered on the absorbers, there was no evidence for clustering.
We performed the same analysis on simulated data sets from numerical simulations. There, we found that the clustering of galaxies around the simulated absorbers is weaker than that of the galaxies with each other, by a factor of approximately two. This is consistent with damped absorbers being associated with low-luminosity galaxies.