Related papers: Decoding the Early Universe: Exploring a Merger Sc…

In this work we study the intracluster medium of a galaxy cluster at the cosmic noon: JKCS041 at z=1.803. A 28h long Sunyaev-Zel'dovich (SZ) observation using MUSTANG-2 allows us to detect JKCS041, even if intrinsically extremely faint…

[Abridged] We report the discovery of JKCS041, a massive near-infrared selected cluster of galaxies z=1.9. The cluster was originally discovered using a modified red-sequence method and was also detected in follow-up Chandra data as…

Galaxy clusters, the most massive collapsed structures, have been routinely used to determine cosmological parameters. When using clusters for cosmology, the crucial assumption is that they are relaxed. However, subarcminute resolution…

We present Hubble Space Telescope imaging and grism spectroscopy in the field of the distant galaxy cluster JKCS 041 using the Wide Field Camera 3. We confirm that JKCS 041 is a rich cluster and derive a redshift z=1.80 via the…

The galaxy cluster XLSSC~122 is a rare system at $z = 1.98$, hosting surprisingly evolved member galaxies when the Universe was only one-third of its present age. Leveraging deep JWST/NIRCam imaging, we perform a weak-lensing analysis and…

Galaxy cluster mergers that exhibit clear dissociation between their dark matter, intracluster gas, and stellar components are great laboratories for probing dark matter properties. Mergers that are binary and in the plane of the sky have…

Using deep two-color near-infrared HST imaging and unbiased grism spectroscopy we present a detailed study of the z=1.803 JKCS041 cluster. Uniquely, for a high redshift cluster, we confirm a mass of $\log M=14.2$ in solar units using four…

The evolution of the properties of the hot gas that fills the potential well of galaxy clusters is poorly known, since models are unable to give robust predictions and observations lack a sufficient redshift leverage and are affected by…

Above redshift z ~ 1.4, we known little or nothing about the stellar ages of red galaxies in clusters, yet at these high redshifts important changes are predicted by current renditions of galaxy formation models embedded in the standard…

Observations reveal that the peaks of the X-ray map and the Sunyaev-Zel'dovich (SZ) effect map of some galaxy clusters are offset from each other. In this paper, we perform a set of hydrodynamical simulations of mergers of two galaxy…

We present data for 16 galaxies in the overdensity JKCS 041 at $z \simeq 1.80$ as part of the K-band Multi-Object Spectrograph (KMOS) Cluster Survey (KCS). With 20-hour integrations, we have obtained deep absorption-line spectra from which…

We used the Hubble Space Telescope to take a wide field, multicolor image of the high redshift cluster MS1054-03 at z=0.83. The Keck telescope was used to take 200 redshifts in the field. We have a total of 81 spectroscopically confirmed…

Galaxy cluster mergers are rich sources of information to test cluster astrophysics and cosmology. However, cluster mergers produce complex projected signals that are difficult to interpret physically from individual observational probes.…

Observations over the past decade have shown that galaxy clusters undergo the most transformative changes during the $z = 1.5 - 2$ epoch. However, challenges such as low lensing efficiency, high shape measurement uncertainty, and a scarcity…

We present a detailed analysis of predicted galaxy-galaxy merger fractions and rates in the Millennium simulation and compare these with the most up to date observations of the same quantities up to z~3. We carry out our analysis by…

We present DLSCL J0916.2+2951 (z=0.53), a newly discovered major cluster merger in which the collisional cluster gas has become dissociated from the collisionless galaxies and dark matter. We identified the cluster using optical and weak…

We compile a sample of spectroscopically- and photometrically-selected cluster galaxies from four high-redshift galaxy clusters ($1.59 < z < 1.71$) from the Spitzer Adaptation of the Red-Sequence Cluster Survey (SpARCS), and a comparison…

Using CANUCS imaging we found an apparent major merger of two $z\sim5$ ultra-low-mass galaxies ($M_\star\sim10^{7}M_\odot$ each) that are doubly imaged and magnified $\sim$12-15$\times$ by the lensing cluster MACS 0417. Both galaxies are…

X-ray and radio observations of CIZA J2242.8+5301 suggest that it is a major cluster merger. Despite being well studied in the X-ray, and radio, little has been presented on the cluster structure and dynamics inferred from its galaxy…

Recent observations reveal detailed structures of mergers in galaxy clusters. Moving cold fronts could be identified as remnants of subclusters. They are believed to mark the late stage of a merging process. Dynamics, geometry and extension…