ner_tags: O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B-Citation I-Citation I-Citation I-Citation O B-Citation I-Citation I-Citation I-Citation O O O O B-CelestialObject I-CelestialObject O O O O O O O B-Citation I-Citation I-Citation I-Citation O O O O O O O O O O O O O O O O O O B-Citation I-Citation I-Citation I-Citation O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B-Citation I-Citation O O O O O O O O O O O O O O O B-Citation I-Citation I-Citation I-Citation I-Citation O O O O O B-Model I-Model I-Model I-Model O O B-Model I-Model I-Model I-Model O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B-Model I-Model I-Model O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O
tokens: medium these interactions can alter the structure of a galaxy, but the degree to which it is affected also depends on whether it was previously pre-processed. For example, dark matter haloes that were previously in a group environment tend to lose mass more slowly in the cluster environment as the more weakly bound dark matter in the outer halo was already removed in the group (Joshi, Wadsley Parker 2017 ; Han et al. 2018 ). Also, in some Virgo cluster dwarf ellipticals, counter-rotating cores have been observed (Toloba et al. 2014 ). Such features are very difficult to reproduce through the action of the cluster tides or harassment alone (González-García, Aguerri Balcells 2005 ). Thus, mergers in a previous group environment are likely required to explain the presence of such features in galaxies that are now cluster members. In addition to pre-processing, it is important to take into account that galaxies entering the cluster in a group face the combined environmental influence of both group and cluster, and it may be several gigayears until groups can be completely dissociated and virialized within the cluster (Cohn 2012 ). This process, arising in group-cluster mergers, is often referred to as post-processing . In Vijayaraghavan Ricker ( 2013 ), this process was studied using N -body cosmological simulations combined with idealized N -body/hydrodynamical simulations. They study the effects that the merger has on both group and cluster: there is an enhancement of the galaxy–galaxy merger rate during the pericentric passage of the group in the cluster; the merger shock leads to an increase in the ram pressure acting on both the group and the cluster galaxies; and the group galaxies may become tidally truncated. In this context it is clear that to fully understand the processes that are triggering changes in the cluster galaxy population it is crucial to understand their environmental history. While the quantity of pre-processed galaxies in clusters has been shown to be quite significant, as has the effect of the group environment upon them, our understanding of what happens to these galaxies once their hosts enter the cluster, the post-processing stage, has not been explored in so much detail. Thus, in the study presented here, we focus on the consequences of the group falling into the cluster environment. Using a set of high-resolution N -body simulations of galaxy clusters, we identify host and satellite haloes at different redshifts, and then track their evolution while they are under the influence of the cluster environment. We specifically include satellites that are stripped from their host halo by the cluster tides in order to better understand the role of the cluster in the dissociation of substructure. Understanding how groups breakup in clusters could potentially help us identify these pre-processed galaxies, once they have left their groups and mixed with the cluster population. However, as we will show later in this