Galaxy pairs in The Three Hundred simulations: a study on the performance of observational pair-finding techniques
arXiv:2207.13451 · doi:10.1093/mnras/stac2127
Abstract
Close pairs of galaxies have been broadly studied in the literature as a way to understand galaxy interactions and mergers. In observations they are usually defined by setting a maximum separation in the sky and in velocity along the line of sight, and finding galaxies within these ranges. However, when observing the sky, projection effects can affect the results, by creating spurious pairs that are not close in physical distance. In this work we mimic these observational techniques to find pairs in The Three Hundred simulations of clusters of galaxies. The galaxies' 3D coordinates are projected into 2D, with Hubble flow included for their line-of-sight velocities. The pairs found are classified into "good" or "bad" depending on whether their 3D separations are within the 2D spatial limit or not. We find that the fraction of good pairs can be between 30 and 60 per cent depending on the thresholds used in observations. Studying the ratios of observable properties between the pair member galaxies, we find that the likelihood of a pair being "good" can be increased by around 40, 20 and 30 per cent if the given pair has, respectively, a mass ratio below 0.2, metallicity ratio above 0.8, or colour ratio below 0.8. Moreover, shape and stellar-to-halo mass ratios respectively below 0.4 and 0.2 can increase the likelihood by 50 to 100 per cent. These results suggest that these properties can be used to increase the chance of finding good pairs in observations of galaxy clusters and their environment.
15 pages, 10 figures. Published in MNRAS; typos corrected
References in corpus (22)
- The bulk of the black hole growth since z~1 occurs in a secular universe: No major merger-AGN connection
- Dark matter and cosmic structure
- Chemical enrichment of galaxy clusters from hydrodynamical simulations
- The Redshift Evolution of Wet, Dry, and Mixed Galaxy Mergers from Close Galaxy Pairs in the DEEP2 Galaxy Redshift Survey
- A calibration of the relation between the abundance of close galaxy pairs and the rate of galaxy mergers
- A definitive merger-AGN connection at z~0 with CFIS: mergers have an excess of AGN and AGN hosts are more frequently disturbed
- A refined sub-grid model for black hole accretion and AGN feedback in large cosmological simulations
- Observational constraints on the merger history of galaxies since : Probabilistic galaxy pair counts in the CANDELS fields
- Interaction-induced star formation in a complete sample of 10^5 nearby star-forming galaxies
- Galaxy And Mass Assembly (GAMA): Galaxy close-pairs, mergers, and the future fate of stellar mass
- The GALEX Ultraviolet Virgo Cluster Survey (GUViCS). IV: The role of the cluster environment on galaxy evolution
- Interactions, star formation and AGN activity
- A consistent measure of the merger histories of massive galaxies using close-pair statistics I: Major mergers at
- Pressure of the hot gas in simulations of galaxy clusters
- The Three Hundred Project: Backsplash galaxies in simulations of clusters
- Compact groups in theory and practice - III. Compact groups of galaxies in the Sixth Data Release of the Sloan Digital Sky Survey
- The merger fraction of active and inactive galaxies in the local Universe through an improved non-parametric classification
- Compact groups in theory and practice - I. The spatial properties of compact groups
- Galaxy pairs in the Sloan Digital Sky Survey -- XIV. Galaxy mergers do not lie on the Fundamental Metallicity Relation
- The Three Hundred Project: Substructure in hydrodynamical and dark matter simulations of galaxy groups around clusters
- Leavers and remainers: Galaxies split by group-exit
- Compact groups from semi-analytical models of galaxy formation -- III: purity and completeness of Hickson-like catalogues