Related papers: ALMACAL. XI. Over-densities as signposts to proto-…
Using spectroscopic observations taken for the VIMOS Ultra-Deep Survey (VUDS) we report here on the discovery of PCl J1001+0220, a massive proto-cluster located at $z_{spec}\sim4.57$ in the COSMOS field. The proto-cluster was initially…
For a complete picture of galaxy cluster formation, it is important that we start probing the early epoch of z~2-7 during which clusters and their galaxies first began to form. Because the study of these so-called "proto-clusters" is…
To demonstrate the feasibility of studying the epoch of massive galaxy cluster formation in a more systematic manner using current and future galaxy surveys, we report the discovery of a large sample of proto-cluster candidates in the 1.62…
We have discovered a highly significant over-density of galaxies at z=2.300+/-0.015 in the course of a redshift survey designed to select star-forming galaxies in the redshift range z=2.3+/-0.4 in the field of the bright z=2.72 QSO…
High-redshift protoclusters are crucial for understanding the formation of galaxy clusters and the evolution of galaxies in dense environments. The James Webb Space Telescope (JWST), with its unprecedented near-infrared sensitivity, enables…
We present the spectroscopic confirmation of a $z=2.45$ proto-cluster. Its member galaxies lie within a radius of 1.4Mpc (physical) on the sky and within $\Delta v \pm 700$km/s along the line of sight. We estimate an overdensity of 10,…
We present the serendipitous discovery of an overdensity of submillimeter galaxies (SMGs) in the field of SDSSJ0909-0108, a massive z~0.7 post-starburst galaxy from the SQuIGGLE survey. ALMA observations at 870um and 2mm reveal six galaxies…
The most luminous quasars at $z > 6$ are suspected to be both highly clustered and reside in the most massive dark matter halos in the early Universe, making them prime targets to search for galaxy overdensities and/or protoclusters. We…
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…
There is controversy whether dusty starbursts selected at submillimeter wavelengths can trace galaxy overdensities. We perform the first systematic search for protoclusters around a homogeneously selected sample of 12 spectroscopically…
Weak gravitational lensing provides a potentially powerful method for the detection of clusters. In addition to cluster candidates, a large number of objects with possibly no optical or X-ray component have been detected in shear-selected…
Investigating the processes by which galaxies rapidly build up their stellar mass during the peak of their star formation ($z=2$--$3$) is crucial to advancing our understanding of the assembly of large-scale structures. We report the…
We compare the highly clustered populations of very high redshift galaxies with proto-clusters identified numerically in a standard $\Lambda$CDM universe ($\Omega_0=0.3, \lambda_0=0.7$) simulation. We evolve 256^3 dark matter particles in a…
We study the characteristics of galaxy protoclusters using the latest L-galaxies semi-analytic model. Searching for protoclusters on a scale of $\sim 10 \, \mathrm{cMpc}$ gives an excellent compromise between the completeness and purity of…
Using new spectroscopic observations obtained as part of the VIMOS Ultra-Deep Survey (VUDS), we perform a systematic search for overdense environments in the early universe ($z>2$) and report here on the discovery of Cl J0227-0421, a…
We have surveyed the core regions of the z = 1.46 cluster XCS J2215.9-1738 with the Atacama Large Millimeter Array (ALMA) and the MUSE-GALACSI spectrograph on the VLT. We obtained high spatial resolution observations with ALMA of the 1.2 mm…
Galaxy proto-clusters at z >~ 2 provide a direct probe of the rapid mass assembly and galaxy growth of present day massive clusters. Because of the need of precise galaxy redshifts for density mapping and the prevalence of star formation…
We performed a systematic spectroscopic observation of a protocluster at $z=6.01$ in the Subaru Deep Field. We took spectroscopy for all 53 $i'$-dropout galaxies down to $z'=27.09\,\mathrm{mag}$ in/around the protocluster region. From these…
Galaxy protoclusters, which will eventually grow into the massive clusters we see in the local universe, are usually traced by locating overdensities of galaxies. Large spectroscopic surveys of distant galaxies now exist, but their…
We present a new, objectively selected, sample of galaxy overdensities detected in the Hubble Space Telescope Medium Deep Survey. These clusters/groups were found using an automated procedure which involved searching for statistically…