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The kinematics of cluster galaxies via velocity dispersion profiles

Bilton, Lawrence E.; Pimbblet, Kevin A.


Lawrence E. Bilton


© 2018 The Author(s). We present an analysis of the kinematics of a sample of 14 galaxy clusters via velocity dispersion profiles (VDPs), compiled using cluster parameters defined within the X-Ray Galaxy Clusters Database (BAX) cross-matched with data from the Sloan Digital Sky Survey (SDSS). We determine the presence of substructure in the clusters from the sample as a proxy for recent core mergers, resulting in 4 merging and 10 non-merging clusters to allow for comparison between their respective dynamical states. We create VDPs for our samples and divide them by mass, colour, and morphology to assess how their kinematics respond to the environment. To improve the signal-to-noise ratio our galaxy clusters are normalized and co-added to a projected cluster radius at 0.0-2.5r200. We find merging cluster environments possess an abundance of a kinematically active (rising VDP) mix of red and blue elliptical galaxies, which is indicative of infalling substructures responsible for pre-processing galaxies. Comparatively, in non-merging cluster environments galaxies generally decline in kinematic activity as a function of increasing radius, with bluer galaxies possessing the highest velocities, likely as a result of fast infalling field galaxies. However, the variance in kinematic activity between blue and red cluster galaxies across merging and non-merging cluster environments suggests galaxies exhibit differing modes of galaxy accretion on to a cluster potential as a function of the presence of a core merger.

Journal Article Type Article
Publication Date Dec 1, 2018
Journal Monthly notices of the Royal Astronomical Society
Print ISSN 0035-8711
Electronic ISSN 1365-2966
Publisher Oxford University Press (OUP)
Peer Reviewed Peer Reviewed
Volume 481
Issue 2
Pages 1507-1521
APA6 Citation Bilton, L. E., & Pimbblet, K. A. (2018). The kinematics of cluster galaxies via velocity dispersion profiles. Monthly notices, containing papers, abstracts of papers, and reports of the proceedings of the Society, 481(2), 1507-1521.
Keywords Space and Planetary Science; Astronomy and Astrophysics
Publisher URL


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Copyright Statement
© 2018 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society

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