Physics and Astronomy
Using a volume-limited sample of 550 groups from the Galaxy And Mass Assembly Galaxy Group Catalogue spanning the halo mass range , we investigate the merging potential of central Brightest Group Galaxies (BGGs). We use spectroscopically confirmed close-companion galaxies as an indication of the potential stellar mass buildup of low-redshift BGGs, z ≤ 0.2. We identify 17 close-companion galaxies with projected separations rp < 30 kpc, relative velocities Δv ≤ 300 km s−1, and stellar mass ratios MBGG/MCC ≤ 4 relative to the BGG. These close-companion galaxies yield a total pair fraction of 0.03 ± 0.01. Overall, we find that BGGs in our sample have the potential to grow in stellar mass due to mergers by 2.2 ± 1.5% Gyr−1. This is lower than the stellar mass growth predicted by current galaxy evolution models.
Original Publication Information
Banks, K., et al. “Galaxy And Mass Assembly (GAMA): The Merging Potential of Brightest Group Galaxies” 2021, The Astrophysical Journal, 921(1): 1-9.
Banks, K.; Brough, S.; Holwerda, Benne; Hopkins, A. M.; López-Sánchez, Á. R.; Phillipps, S.; Pimbblet, K. A.; and Robotham, A. S. G., "Galaxy And Mass Assembly (GAMA): The Merging Potential of Brightest Group Galaxies" (2021). Faculty Scholarship. 826.
This article was originally published in The Astrophysical Journal, volume 921, issue 47, in November 2021.