2013/08/06 by Rukmani Vijayaraghavan, P. M. Ricker, Paul M. Ricker · 110 citations
Physics and Astronomy · #Astronomy #Astronomy and Astrophysical Research #Astrophysics #Astrophysics and Star Formation Studies #Brightest cluster galaxy #Cluster (spacecraft) #Dwarf galaxy #Elliptical galaxy #Galaxies: Formation, Evolution, Phenomena #Galaxy #Galaxy cluster #Galaxy group #Galaxy merger #Physics #Ram pressure #Star formation #astro-ph.CO
paper · pdf · doi:10.1093/mnras/stt1485
published in Monthly Notices of the Royal Astronomical Society 435(3), 2713-2735 (Oxford University Press) · Accepted for publication in MNRAS. 25 pages, 21 figures
arxiv created 2013/08/06 · openalex publication_date 2013/09/04 · arxiv updated 2013/09/05 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Galaxies in clusters are more likely to be of early type and to have lower star formation rates than galaxies in the field. Recent observations and simulations suggest that cluster galaxies may be ‘pre-processed’ by group or filament environments and that galaxies that fall into a cluster as part of a larger group can stay coherent within the cluster for up to one orbital period (‘post-processing’). We investigate these ideas by means of a cosmological N-body simulation and idealized N-body plus hydrodynamics simulations of a group–cluster merger. We find that group environments can contribute significantly to galaxy pre-processing by means of enhanced galaxy–galaxy merger rates, removal of galaxies’ hot halo gas by ram pressure stripping and tidal truncation of their galaxies. Tidal distortion of the group during infall does not contribute to pre-processing. Post-processing is also shown to be effective: galaxy–galaxy collisions are enhanced during a group's pericentric passage within a cluster, the merger shock enhances the ram pressure on group and cluster galaxies and an increase in local density during the merger leads to greater galactic tidal truncation.