Skip to main content

Research Repository

Advanced Search

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.

The impact of protocluster environments at z = 1.6 Thumbnail


Elizabeth A. Cooke

Stuart I. Muldrew

William G. Hartley

Professor of Astrophysics

Christopher J. Conselice

C.J. Simpson


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.


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.

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
Keywords galaxies: clusters: indivudial: CI 0218.3-0510, galaxies: evolution, galaxies:high-redshift
Public URL
Publisher URL
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.
Contract Date Oct 24, 2016


You might also like

Downloadable Citations