The Violent Youth of Bright and Massive Cluster Galaxies and Their Maturation over 7 Billion Years

Authors

B. Ascaso, Instituto de Astrofísica de Andalucía, Spain
B. C. Lemaux, Aix Marseille Université, France
L. M. Lubin, University of California - Davis
R. R. Gal, University of Hawaii
Dale D. Kocevski, University of KentuckyFollow
N. Rumbaugh, University of California - Davis
G. Squires, California Institute of Technology

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.

Document Type

Article

Publication Date

7-21-2014

Notes/Citation Information

Published in Monthly Notices of the Royal Astronomical Society, v. 442, no. 1, 589-615.

This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society ©: 2014 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.

Digital Object Identifier (DOI)

http://dx.doi.org/10.1093/mnras/stu877

Funding Information

BA acknowledges the support from Junta de Andalucía, through the Excellence Project P08-TIC-3531 and the Spanish Ministry for Science and Innovation, through grants AYA2010-22111-C03-01 and CSD2007-00060. Part of this work was supported by funding from the European Research Council Advanced Grant ERC-2010-AdG-268107-EARLY. In addition, BCL acknowledges the support from the National Science Foundation under grant AST-0907858 and by NASA through a grant from the Space Telescope Science Institute (HST-GO-11003), which is operated by the Association of Universities for Research in Astronomy, Incorporated, under NASA contract NAS5-26555. Portions of this work were based on observations made with the Spitzer Space Telescope, which is operated by the Jet Propulsion Laboratory, California Institute of Technology under a contract with NASA. Support for this work was provided by NASA through an award issued by JPL/Caltech. A part of this work was based on data obtained by the SDSS, which is managed by the Astrophysical Research Consortium for the Participating Institutions. Funding for the SDSS has been provided by the Alfred P. Sloan Foundation, the Participating Institutions, the National Science Foundation, the US Department of Energy, the National Aeronautics and Space Administration, the Japanese Monbukagakusho, the Max Planck Society, and the Higher Education Funding Council for England. The SDSS website is http://www.sdss.org/. A portion of the spectrographic data presented herein were obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation. We wish to thank the indigenous Hawaiian community for allowing us to be guests on their sacred mountain; we are most fortunate to be able to conduct observations from this site.

Related Content

Portions of this work were based on observations made with the Spitzer Space Telescope, which is operated by the Jet Propulsion Laboratory, California Institute of Technology under a contract with NASA. . . . A part of this work was based on data obtained by the SDSS, which is managed by the Astrophysical Research Consortium for the Participating Institutions. . . . A portion of the spectrographic data presented herein were obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration.

Repository Citation

Ascaso, B.; Lemaux, B. C.; Lubin, L. M.; Gal, R. R.; Kocevski, Dale D.; Rumbaugh, N.; and Squires, G., "The Violent Youth of Bright and Massive Cluster Galaxies and Their Maturation over 7 Billion Years" (2014). Physics and Astronomy Faculty Publications. 278.
https://uknowledge.uky.edu/physastron_facpub/278