The violent youth of bright and massive cluster galaxies and their maturation over 7 billion years

DOI: 
10.1093/mnras/stu877
Publication date: 
21/07/2014
Main author: 
Ascaso B.
IAA authors: 
Ascaso B.
Authors: 
Ascaso B., Lemaux B.C., Lubin L.M., Gal R.R., Kocevski D.D., Rumbaugh N., Squires G.
Journal: 
Monthly Notices of the Royal Astronomical Society
Publication type: 
Article
Volume: 
442
Pages: 
589-615
Number: 
Abstract: 
In this study, we investigate the formation and evolution mechanisms of the brightest cluster galaxies (BCGs) over cosmic time. At high redshift (z ∼ 0.9), we selected BCGs and most massive cluster galaxies (MMCGs) from the Cl1604 supercluster and compared them to low-redshift (z ∼ 0.1) counterparts drawn from the MCXC meta-catalogue, supplemented by Sloan Digital Sky Survey imaging and spectroscopy. We observed striking differences in the morphological, colour, spectral, and stellar mass properties of the BCGs/MMCGs in the two samples. High-redshift BCGs/MMCGs were, in many cases, star-forming, late-type galaxies, with blue broad-band colours, properties largely absent amongst the low-redshift BCGs/MMCGs. The stellar mass of BCGs was found to increase by an average factor of 2.51 ± 0.71 from z ∼ 0.9 to z ∼ 0.1. Through this and other comparisons, we conclude that a combination of major merging (mainly wet or mixed) and in situ star formation are the main mechanisms which build stellar mass in BCGs/MMCGs. The stellar mass growth of the BCGs/MMCGs also appears to grow in lockstep with both the stellar baryonic and total mass of the cluster. Additionally, BCGs/MMCGs were found to grow in size, on average, a factor of ∼3, while their average Sérsic index increased by ∼0.45 from z ∼ 0.9 to z ∼ 0.1, also supporting a scenario involving major merging, though some adiabatic expansion is required. These observational results are compared to both models and simulations to further explore the implications on processes which shape and evolve BCGs/MMCGs over the past ∼7 Gyr. © 2014 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society.
Database: 
WOK
SCOPUS
ADS
URL: 
https://ui.adsabs.harvard.edu/#abs/2014MNRAS.442..589A/abstract
ADS Bibcode: 
2014MNRAS.442..589A
Keywords: 
Galaxies: clusters: general; Galaxies: elliptical and lenticular, cD; Galaxies: evolution; Galaxies: formation; Techniques: photometric; Techniques: spectroscopic