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The KMOS Cluster Survey (KCS) II - The Effect of Environment on the Structural Properties of Massive Cluster Galaxies at Redshift $1.39 \lt z \lt1.61$

Chan, J.C.C.; Beifiori, A.; Saglia, R.P.; Mendel, J.T.; Stott, J.P.; Bender, R.; Galametz, A.; Wilman, D.J.; Cappellari, M.; Davies, R.L.; Houghton, R.C.W.; Prichard, L.J.; Lewis, I.J.; Sharples, R.; Wegner, M.

The KMOS Cluster Survey (KCS) II - The Effect of Environment on the Structural Properties of Massive Cluster Galaxies at Redshift $1.39 \lt z \lt1.61$ Thumbnail


Authors

J.C.C. Chan

A. Beifiori

R.P. Saglia

J.T. Mendel

J.P. Stott

R. Bender

A. Galametz

D.J. Wilman

M. Cappellari

R.L. Davies

R.C.W. Houghton

L.J. Prichard

I.J. Lewis

M. Wegner



Abstract

We present results on the structural properties of massive passive galaxies in three clusters at 1.39 < z < 1.61 from the KMOS Cluster Survey. We measure light-weighted and mass-weighted sizes from optical and near-infrared Hubble Space Telescope imaging and spatially resolved stellar mass maps. The rest-frame R-band sizes of these galaxies are a factor of ~2–3 smaller than their local counterparts. The slopes of the relation between the stellar mass and the light-weighted size are consistent with recent studies in clusters and the field. Their mass-weighted sizes are smaller than the rest-frame R-band sizes, with an average mass-weighted to light-weighted size ratio that varies between ~0.45 and 0.8 among the clusters. We find that the median light-weighted size of the passive galaxies in the two more evolved clusters is ~24% larger than that for field galaxies, independent of the use of circularized effective radii or semimajor axes. These two clusters also show a smaller size ratio than the less evolved cluster, which we investigate using color gradients to probe the underlying ${M}_{* }/{L}_{{{\rm{H}}}_{160}}$ gradients. The median color gradients are ∇z − H ~ −0.4 mag dex−1, twice the local value. Using stellar populations models, these gradients are best reproduced by a combination of age and metallicity gradients. Our results favor the minor merger scenario as the dominant process responsible for the observed galaxy properties and the environmental differences at this redshift. The environmental differences support that clusters experience accelerated structural evolution compared to the field, likely via an epoch of enhanced minor merger activity during cluster assembly.

Citation

Chan, J., Beifiori, A., Saglia, R., Mendel, J., Stott, J., Bender, R., …Wegner, M. (2018). The KMOS Cluster Survey (KCS) II - The Effect of Environment on the Structural Properties of Massive Cluster Galaxies at Redshift $1.39 \lt z \lt1.61$. Astrophysical Journal, 856(1), Article 8. https://doi.org/10.3847/1538-4357/aaadb4

Journal Article Type Article
Acceptance Date Feb 5, 2018
Online Publication Date Mar 20, 2018
Publication Date Mar 1, 2018
Deposit Date Mar 11, 2018
Publicly Available Date Mar 13, 2018
Journal Astrophysical Journal
Print ISSN 0004-637X
Publisher American Astronomical Society
Peer Reviewed Peer Reviewed
Volume 856
Issue 1
Article Number 8
DOI https://doi.org/10.3847/1538-4357/aaadb4
Public URL https://durham-repository.worktribe.com/output/1365258
Related Public URLs http://adsabs.harvard.edu/abs/2018arXiv180201609C

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Copyright Statement
© 2018. The American Astronomical Society. All rights reserved.






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