Improving the descendant relationship of cluster galaxies at z < 1

Abstract

In this work, we study how to improve well-known techniques for detecting progenitors/descendants of galaxies, such as the NDpredict program, when applied to galaxies in clusters. The improvement of this particular method is based on the use of the red sequence of galaxies in those environments. Objects close to the red sequence in the color and magnitude diagram are more likely to belong to the cluster. This defines a probability scale which is then combined with the one generated by NDpredict. This procedure is optimized for the study of galaxies in clusters over different epochs. Our main result is that, for a sample composed of $120$ clusters, with masses greater than ${10}^{13.25}{M}_{\odot }$, selected from the IllustrisTNG simulations (namely, the TNG100 runs). In $99\%$ of the cases (i.e., $119$ systems), we obtain better performance with the red sequence method in comparison to the original NDpredict, and the average gain obtained is $28\%$ in the identification of descendants for this sample of cluster galaxies.