53 research outputs found
The Massive and Distant Clusters of WISE Survey V: Extended Radio Sources in Massive Galaxy Clusters at z~1
We present the results from a pilot study with the Karl G. Jansky Very Large
Array (JVLA) to determine the radio morphologies of extended radio sources and
the properties of their host-galaxies in 10 massive galaxy clusters at z~1, an
epoch in which clusters are assembling rapidly. These clusters are drawn from a
parent sample of WISE-selected galaxy clusters that were cross-correlated with
the VLA Faint Images of the Radio Sky at Twenty-Centimeters survey (FIRST) to
identify extended radio sources within 1 of the cluster centers. Out
of the ten targeted sources, six are FR II sources, one is an FR I source, and
three sources have undetermined morphologies. Eight radio sources have
associated Spitzer data, 75% presenting infrared counterparts. A majority of
these counterparts are consistent with being massive galaxies. The angular
extent of the FR sources exhibits a strong correlation with the cluster-centric
radius, which warrants further investigation with a larger sample.Comment: accepted to Ap
The Massive and Distant Clusters of WISE Survey: SZ effect Verification with the Atacama Compact Array -- Localization and Cluster Analysis
The Massive and Distant Clusters of WISE Survey (MaDCoWS) provides a catalog
of high-redshift () infrared-selected galaxy
clusters. However, the verification of the ionized intracluster medium,
indicative of a collapsed and nearly virialized system, is made challenging by
the high redshifts of the sample members. The main goal of this work is to test
the capabilities of the Atacama Compact Array (ACA; also known as the Morita
Array) Band 3 observations, centered at about 97.5 GHz, to provide robust
validation of cluster detections via the thermal Sunyaev-Zeldovich (SZ) effect.
Using a pilot sample that comprises ten MaDCoWS galaxy clusters, accessible to
ACA and representative of the median sample richness, we infer the masses of
the selected galaxy clusters and respective detection significance by means of
a Bayesian analysis of the interferometric data. Our test of the "Verification
with the ACA - Localization and Cluster Analysis" (VACA LoCA) program
demonstrates that the ACA can robustly confirm the presence of the virialized
intracluster medium in galaxy clusters previously identified in full-sky
surveys. In particular, we obtain a significant detection of the SZ effect for
seven out of the ten VACA LoCA clusters. We note that this result is
independent of the assumed pressure profile. However, the limited angular
dynamic range of the ACA in Band 3 alone, short observational integration
times, and possible contamination from unresolved sources limit the detailed
characterization of the cluster properties and the inference of the cluster
masses within scales appropriate for the robust calibration of mass-richness
scaling relations.Comment: 19 pages (including appendices), 14 figures, and 4 tables; accepted
for publication in A&
The Massive and Distant Clusters of WISE Survey: MOO J1142+1527, a 10^(15) M_⊙ Galaxy Cluster at z = 1.19
We present confirmation of the cluster MOO J1142+1527, a massive galaxy cluster discovered as part of the Massive and Distant Clusters of WISE Survey. The cluster is confirmed to lie at z = 1.19, and using the Combined Array for Research in Millimeter-wave Astronomy we robustly detect the Sunyaev–Zel'dovich (SZ) decrement at 13.2σ. The SZ data imply a mass of M_(200m) = (1.1 ± 0.2) × 10^(15)M_⊙, making MOO J1142+1527 the most massive galaxy cluster known at z > 1.15 and the second most massive cluster known at z > 1. For a standard ΛCDM cosmology it is further expected to be one of the ~5 most massive clusters expected to exist at z ≥ 1.19 over the entire sky. Our ongoing Spitzer program targeting ~1750 additional candidate clusters will identify comparably rich galaxy clusters over the full extragalactic sky
The Massive and Distant Clusters of WISE Survey VI: Stellar Mass Fractions of a Sample of High-Redshift Infrared-selected Clusters
We present measurements of the stellar mass fractions () for a
sample of high-redshift () infrared-selected galaxy
clusters from the Massive and Distant Clusters of WISE Survey (MaDCoWS) and
compare them to the stellar mass fractions of Sunyaev-Zel'dovich (SZ)
effect-selected clusters in a similar mass and redshift range from the South
Pole Telescope (SPT)-SZ Survey. We do not find a significant difference in mean
between the two selection methods, though we do find an unexpectedly
large range in for the SZ-selected clusters. In addition, we measure
the luminosity function of the MaDCoWS clusters and find ,
similar to other studies of clusters at or near our redshift range. Finally, we
present SZ detections and masses for seven MaDCoWS clusters and new
spectroscopic redshifts for five MaDCoWS clusters. One of these new clusters,
MOO J1521+0452 at , is the most distant MaDCoWS cluster confirmed to
date.Comment: Accepted to Ap
- …