The impact of protocluster environments at z = 1.6

Hatch, Nina A. and Cooke, Elizabeth A. and Muldrew, Stuart I. and Hartley, William G. and Almaini, O. and Conselice, C.J. and Simpson, C.J. (2016) The impact of protocluster environments at z = 1.6. Monthly Notices of the Royal Astronomical Society, 464 (1). pp. 876-884. ISSN 1365-2966

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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.

Item Type: Article
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.
Keywords: galaxies: clusters: indivudial: CI 0218.3-0510, galaxies: evolution, galaxies:high-redshift
Schools/Departments: University of Nottingham, UK > Faculty of Science > School of Physics and Astronomy
Identification Number: https://doi.org/10.1093/mnras/stw2359
Depositing User: Eprints, Support
Date Deposited: 24 Oct 2016 10:40
Last Modified: 25 Oct 2016 14:31
URI: http://eprints.nottingham.ac.uk/id/eprint/37861

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