Related papers: JKCS041: a Coma cluster progenitor at z=1.803

We report the discovery of a compact supercluster structure at z=0.9. The structure comprises three optically-selected clusters, all of which are detected in X-rays and spectroscopically confirmed to lie at the same redshift. The Chandra…

We present joint X-ray and optical observations of the high redshift (z~0.83) lensing cluster CLJ0152.7-1357 made with the Chandra X-ray Observatory and the Keck telescope. We confirm the existence of significant substructure at both X-ray…

Galaxy clusters are the most massive gravitationally bound structures in the universe and serve as tracers of the assembly of large-scale structure. Studying their progenitors, proto-clusters, sheds light on the earliest stages of cluster…

We report the discovery of a previously unknown massive Galactic star cluster at l=29.22, b=-0.20. Identified visually in mid-IR images from the Spitzer GLIMPSE survey, the cluster contains at least 8 late-type supergiants, based on…

We present a study of the morphological fractions and color-magnitude relation in the most distant X-ray selected galaxy cluster currently known, XMMXCS J2215.9-1738 at z=1.46, using a combination of optical imaging data obtained with the…

K band observations of the galaxy populations of three high redshift (z=0.8-1.0), X-ray selected, massive clusters are presented. The observations reach a depth of K=21.5, corresponding to K*+3.5 mag. The evolution of the galaxy properties…

Many quiescent galaxies discovered in the early Universe by \textit{JWST} raise fundamental questions on when and how these galaxies became and stayed quenched. Making use of the latest version of the semi-analytic model GAEA that provides…

We combine imaging data from the Advanced Camera for Surveys (ACS) with VLT/FORS optical spectroscopy to study the properties of star-forming galaxies in the z=0.837 cluster CL0152-1357. We have morphological information for 24 star-forming…

Massive clusters in our Galaxy are an ideal testbed to investigate the properties and evolution of high mass stars. They provide statistically significant samples of massive stars of uniform ages. To accurately determine the intrinsic…

We analyze the clustering of red and blue galaxies from four samples spanning a redshift range of 0.4<z<2.0 to test the various scenarios by which galaxies evolve onto the red sequence. The data are taken from the UKIDSS Ultra Deep Survey,…

Environmental effects have an important influence on cluster galaxies, but studies at very faint magnitudes (R>21) are almost exclusively based on imaging. We present here a very deep spectroscopic survey of galaxies on the line of sight to…

We report evidence of a fully established galaxy cluster at z=2.07, consisting of a ~20sigma overdensity of red, compact spheroidal galaxies spatially coinciding with extended X-ray emission detected with XMM-Newton. We use VLT VIMOS and…

We present near-infrared observations of the environments around three radio-loud sources (MG1 J0442+0202, 3C 068.2, and MS 1426.9+1052) at redshifts z=1.10,1.57, and 1.83 (respectively), that are surrounded by near-infrared galaxy…

We present a measurement of the low-mass quiescent size-mass relation at Cosmic Noon (1<z<3) from the JWST PRIMER and UNCOVER treasury surveys, which highlights two distinct classes of quiescent galaxies. While the massive population is…

We report the discovery of a galaxy cluster at z=1.62 located in the Spitzer Wide-Area Infrared Extragalactic survey XMM-LSS field. This structure was selected solely as an overdensity of galaxies with red Spitzer/IRAC colors, satisfying…

We present deep I and z' imaging of the colour-selected cluster RzCS 052 and study the color-magnitude relation of this cluster, its scatter, the morphological distribution on the red sequence, the luminosity and stellar mass functions of…

The cosmic time around the z~1 redshift range appears crucial in the cluster and galaxy evolution, since it is probably the epoch of the first mature galaxy clusters. Our knowledge of the properties of the galaxy populations in these…

We present the first sample of 222 high-redshift (z>0.5) star clusters, detected with JWST/NIRCam in 78 magnified galaxies from different galaxy cluster fields. The majority of the systems (~60%) is observed in the very deep NIRCam…

Understanding the process of quenching is one of the major open questions in galaxy evolution, and crucial insights may be obtained by studying quenched galaxies at high redshifts, at epochs when the Universe and the galaxies were younger…

Context: Multi-wavelength surveys for clusters of galaxies are opening a window on the elusive high-redshift (z>1) cluster population. Well controlled statistical samples of distant clusters will enable us to answer questions about their…