The close pair fraction of BCGs since z = 0.5: major mergers dominate recent BCG stellar mass growth
Groenewald, Danièl N.
Loubser, S. Ilani
Skelton, Rosalind E.
Gilbank, David G.
MetadataShow full item record
Using the redMaPPer (red-sequence Matched-filter Probabilistic Percolation) cluster catalogue based on the Sloan Digital Sky Survey (SDSS) photometry, we investigate the importance of major mergers in the stellar mass build-up of brightest cluster galaxies (BCGs) between 0.08 ≤ z ≤ 0.50. We use the SDSS spectroscopy, supplemented with spectroscopic observations from the Southern African Large Telescope at higher redshifts, to identify which BCGs and nearby companions are potential major merger candidates. We use the pair fraction as a proxy for the merger fraction in order to determine how much stellar mass growth the BCGs have experienced due to major mergers. We observe a weak trend of the BCG pair fraction increasing with decreasing redshift, suggesting that major mergers may become more important towards the present day. Major mergers are found to contribute, on average, 24 ± 14 (29 ± 17) per cent towards the stellar mass of a present-day BCG since z = 0.32 (0.45), assuming that half of the companion's stellar mass is accreted on to the BCG. Furthermore, using our merger results in conjunction with predictions from two recent semi-analytical models along with observational measurements from the literature, we find that major mergers have sufficient stellar material to account for the stellar mass growth of the intracluster light between z = 0.3 and 0
Showing items related by title, author, creator and subject.
Groenewald, D.N.; Loubser, S.I. (Oxford Univ Press, 2014)This article is devoted to the study of the central stellar populations of the brightest cluster galaxies (BCGs). High signal-to-noise ratio, long-slit spectra for a sample of 39 galaxies were fitted against two stellar ...
Loubser, S.I. (Oxford Univ Press, 2014)We present detailed, high spatial and spectral resolution, long-slit observations of four central cluster galaxies (CCGs; Abell 0085, 0133, 0644 and Ophiuchus) recently obtained on the Southern African Large Telescope. ...
Loubser, S.I.; Soechting, I.K. (Oxford Univ Press, 2013)We present detailed integral field unit observations of the central few kiloparsecs of the ionized nebulae surrounding four active central cluster galaxies (CCGs) in cooling flow clusters (Abell 0496, 0780, 1644 and ...