Related papers: Do z>6 quasars reside in protoclusters?

Massive clusters of galaxies have been found as early as 3.9 Billion years (z=1.62) after the Big Bang containing stars that formed at even earlier epochs. Cosmological simulations using the current cold dark matter paradigm predict these…

Galaxy clusters at high redshift present a superb opportunity to study galaxy evolution, with large galaxy samples at fixed distances. Several lines of evidence point towards large formation redshifts and passive evolution for cluster…

We discuss the structural and morphological properties of galaxies in a z=1.62 proto-cluster using near-IR imaging data from Hubble Space Telescope Wide Field Camera 3 data of the Cosmic Assembly Near-IR Deep Extragalactic Legacy Survey…

Numerical simulations of cosmological structure formation show that the Universe's most massive clusters, and the galaxies living in those clusters, assemble rapidly at early times (2.5 < z < 4). While more than twenty proto-clusters have…

Recognizing the properties of the host galaxies of quasi-stellar objects (QSOs) is essential to understand the suspected coevolution of central supermassive black holes (BHs) and their host galaxies. We selected a subsample of the…

The early growth of high-redshift quasars and their host galaxies raises critical questions about their cosmic evolution. We exploit the angular resolution and sensitivity of NIRCam to investigate the host galaxies of 31 quasars at…

We analyse the detailed distribution of star-forming and post-starburst members in three distant (z = 0.31) galaxy clusters in terms of evolutionary sequences that incorporate secondary bursts of star formation on pre-existing stellar…

Recently, it was suggested that large concentrations or groups of quasars may trace sites of enhanced matter density at medium and high redshifts analogous to how galaxy clusters trace them in nearby space. We have checked existing quasar…

Using ~300,000 photometrically classified quasars, by far the largest quasar sample ever used for such analyses, we study the redshift and luminosity evolution of quasar clustering on scales of ~50 kpc/h to ~20 Mpc/h from redshifts of…

High-redshift ($z > 3$), massive quiescent galaxies (QGs) offer a significant window into early Universe galaxy formation. Previous works have predicted miscellaneous properties for these quiescents, from an overdensity of neighbors to…

QSO near-zones are an important probe of the the ionization state of the IGM at z ~ 6-7, at the end of reionization. We present here high-resolution cosmological 3D radiative transfer simulations of QSO environments for a wide range of host…

We present tentative evidence for primordial clustering, manifested as an excess of color-selected objects in the field of the QSO SDSS J1030+0524 at redshift z=6.28. We have selected objects red in i_{775}-z_{850} on the basis of Hubble…

A comprehensive set of all available magnitudes, colors and redshifts for optically identified QSO absorbers is compiled from the literature. This results in a largely unbiased sample of galaxies at high redshifts, the size of the sample…

A new model for quasar-hosting dark matter halos, meeting two physical conditions, is put forth. First, significant interactions are taken into consideration to trigger quasar activities. Second, satellites in very massive halos at low…

The formation history of globular clusters (GCs) at redshift $z > 4$ remains an unsolved problem. In this work, we use the cosmological, $N$-body hydrodynamical ``zoom-in'' simulation GigaEris to study the properties and formation of…

It is unclear how galaxies and their central supermassive black holes (SMBHs) co-evolve across cosmic time, especially for the non-local universe ($z \gtrsim 0.5$). The High-$z$ Universe probed via Lensing by QSOs (HULQ) project proposes to…

We measure the clustering of a sample of photometrically selected luminous red galaxies around a low redshift (0.2<z<0.6) sample of quasars selected from the Sloan Digital Sky Survey Data Release 5. We make use of a new statistical…

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…

Using one of the largest volumes of the hydrodynamical cosmological simulation suit Magneticum, we study the evolution of protoclusters identified at redshift = 4, with properties similar to SPT2349-56. We identify 42 protoclusters in the…

We study the luminosity function (LF) and clustering properties of 888 H$\alpha$ emitters (HAEs) at $3.75 < z < 6$ in the GOODS-N field. The sample, built from JWST CONGRESS and FRESCO NIRCam grism surveys using a novel redshift assignment…