Rights statement: This is an author-created, un-copyedited version of an article accepted for publication/published in The Astrophysical Journal. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from it. The Version of Record is available online at doi:10.3847/1538-4357/aaadb4
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Research output: Contribution to Journal/Magazine › Journal article › peer-review
}
TY - JOUR
T1 - The KMOS Cluster Survey (KCS) II - The Effect of Environment on the Structural Properties of Massive Cluster Galaxies at Redshift $1.39 1.61$
AU - Chan, Jeffrey C. C.
AU - Beifiori, Alessandra
AU - Saglia, Roberto P.
AU - Mendel, J. Trevor
AU - Stott, John P.
AU - Bender, Ralf
AU - Galametz, Audrey
AU - Wilman, David J.
AU - Cappellari, Michele
AU - Davies, Roger L.
AU - Houghton, Ryan C. W.
AU - Prichard, Laura J.
AU - Lewis, Ian J.
AU - Sharples, Ray
AU - Wegner, Michael
N1 - This is an author-created, un-copyedited version of an article accepted for publication/published in The Astrophysical Journal. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from it. The Version of Record is available online at doi:10.3847/1538-4357/aaadb4
PY - 2018/3/20
Y1 - 2018/3/20
N2 - 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 for field galaxies, independent of the use of circularized effective radii or semi-major 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∗/LH160 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.
AB - 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 for field galaxies, independent of the use of circularized effective radii or semi-major 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∗/LH160 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.
KW - galaxies: clusters: general
KW - galaxies: elliptical and lenticular, cD
KW - galaxies: formation
KW - galaxies: fundamental parameters
KW - galaxies: high redshift
KW - galaxy: evolution
U2 - 10.3847/1538-4357/aaadb4
DO - 10.3847/1538-4357/aaadb4
M3 - Journal article
VL - 856
JO - The Astrophysical Journal
JF - The Astrophysical Journal
SN - 0004-637X
IS - 1
M1 - 8
ER -