The impact of protocluster environments at z = 1.6

Hatch, Nina A.; Cooke, Elizabeth A.; Muldrew, Stuart I.; Hartley, William G.; Almaini, O.; Conselice, Christopher J.; Simpson, C.J.

Abstract

We investigate the effects of dense environments on galaxy evolution by examining how the properties of galaxies in the z = 1.6 protocluster Cl 0218.3−0510 depend on their location. We determine galaxy properties using spectral energy distribution fitting to 14-band photometry, including data at three wavelengths that tightly bracket the Balmer and 4000 Å breaks of the protocluster galaxies. We find that two-thirds of the protocluster galaxies, which lie between several compact groups, are indistinguishable from field galaxies. The other third, which reside within the groups, differ significantly from the intergroup galaxies in both colour and specific star formation rate. We find that the fraction of red galaxies within the massive protocluster groups is twice that of the intergroup region. These excess red galaxies are due to enhanced fractions of both passive galaxies (1.7 times that of the intergroup region) and dusty star-forming galaxies (3 times that of the intergroup region). We infer that some protocluster galaxies are processed in the groups before the cluster collapses. These processes act to suppress star formation and change the mode of star formation from unobscured to obscured.

Citation

Hatch, N. A., Cooke, E. A., Muldrew, S. I., Hartley, W. G., Almaini, O., Conselice, C. J., & Simpson, C. (2017). The impact of protocluster environments at z = 1.6. Monthly Notices of the Royal Astronomical Society, 464(1), 876-884. https://doi.org/10.1093/mnras/stw2359

• Journal Article Type: Article
• Acceptance Date: Sep 15, 2016
• Online Publication Date: Sep 16, 2016
• Publication Date: Jan 1, 2017
• Deposit Date: Oct 24, 2016
• Publicly Available Date: Oct 24, 2016
• Journal: Monthly Notices of the Royal Astronomical Society
• Print ISSN: 0035-8711
• Electronic ISSN: 1365-2966
• Publisher: Oxford University Press
• Peer Reviewed: Peer Reviewed
• Volume: 464
• Issue: 1
• Pages: 876-884
• DOI: https://doi.org/10.1093/mnras/stw2359
• Keywords: galaxies: clusters: indivudial: CI 0218.3-0510, galaxies: evolution, galaxies:high-redshift
• Public URL: https://nottingham-repository.worktribe.com/output/975051
• Publisher URL: http://mnras.oxfordjournals.org/content/464/1/876
• Additional Information: This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society © 2016 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.