Related papers: A census of galaxy constituents in a Coma Progenit…
We present new observations of the field containing the z=3.786 protocluster, PC217.96+32.3. We confirm that it is one of the largest and most overdense high-redshift structures known. Such structures are rare even in the largest…
In the hierarchical theory of galaxy formation, a galaxy overdensity is a hallmark of a massive cosmic structure. However, it is less well understood how different types of galaxies trace the underlying large-scale structure. Motivated by…
Using cosmological hydrodynamic simulations with radiative transfer, we investigate star formation and overdensity ($\delta$) in Coma-type cluster progenitors from $z=14$ to 6. Our simulations reproduce observed $M_{\rm star}$-SFR relations…
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 report the discovery of a large-scale structure containing multiple overdensities at $z= 4.54 \pm 0.03$ in the COSMOS field, with the most prominent one likely infalling towards the recently identified Taralay protocluster. We use…
We present a detailed study of Near-IR selected galaxies in a protocluster field at z = 3.13. Protocluster galaxies are selected using the available mutliwavelength data with the photometric redshift (photo-z) at 2.9 < z < 3.3, reaching a…
JWST has revealed an overabundance of apparent (`Coma'-like) cluster progenitors at $z>5$ that is $\sim$ two (300) times in excess of, and in $2.3\sigma$ ($4\sigma$) tension with, the number density of such objects at present day and…
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…
[Abridged] We characterise a massive proto-cluster at z=2.895 that we found in the COSMOS field using the spectroscopic sample of the VIMOS Ultra-Deep Survey (VUDS). This is one of the rare structures at z~3 not identified around AGNs or…
Protoclusters, the progenitors of galaxy clusters, trace large scale structures in the early Universe and are important to our understanding of structure formation and galaxy evolution. To date, only a handful of protoclusters have been…
We report the discovery of a large-scale structure containing multiple protoclusters at z=3.78 in the Bo\"otes field. The spectroscopic discovery of five galaxies at z=3.783+/-0.002 lying within 1 Mpc of one another led us to undertake a…
We have developed a search methodology to identify galaxy protoclusters at $z>2.74$, and implemented it on a sample of $\sim$14,000 galaxies with previously measured redshifts. The results of this search are recorded in the Candidate…
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 a multiwavelength study of galaxies around D4UD01, a spectroscopically confirmed protocluster at z = 3.24 to investigate environmental trends. 450 galaxies are selected based on Ks band detection with photometric redshifts…
We report the spectroscopic confirmation of a new protocluster in the COSMOS field at $z$ $\sim$ 2.2, COSMOS Cluster 2.2 (CC2.2), originally identified as an overdensity of narrowband selected H$\alpha$ emitting candidates. With only two…
About 2100 star-forming galaxy protocluster candidates at z=1-4 were identified at sub-mm wavelengths in the Planck all sky survey. Follow-up spectroscopic observations of a few candidates have confirmed the presence of actual galaxy…
We study the environments of 6 radio galaxies at 2.2 < z < 2.6 using wide-field near-infrared images. We use colour cuts to identify galaxies in this redshift range, and find that three of the radio galaxies are surrounded by significant…
The progenitors of present-day galaxy clusters offer crucial insight into how galaxies and large-scale structure co-evolve in the early Universe. We present JWST/NIRCam grism spectroscopy of the photometrically identified $z=7.66$…
The redshift range z=2-4 marks a critical transition in large scale structure formation, where the dynamically unrelaxed progenitors of local massive clusters undergo rapid stellar mass assembly. We report the discovery and physical…
We present a population study of several types of galaxies within the protocluster surrounding the radio galaxy MRC0316-257 at z~3.1. In addition to the known population of Ly_alpha emitters (LAEs) and [OIII] emitters, we use colour…