Related papers: Galaxy cluster A2142: halo boundary, `red sequence…
We find, using cosmological simulations of galaxy clusters, that the hot X-ray emitting intra-cluster medium (ICM) enclosed within the outer accretion shock extends out to $R_{\rm shock}\sim(2 - 3) R_{\rm vir}$, where $R_{\rm vir}$ is the…
[Abridged] We present the first results of hydrodynamical simulations that follow the formation of galaxies to z=0 in spherical regions of radius ~20 Mpc/h drawn from the Millennium Simulation. The regions have overdensities that deviate by…
The study of cluster post starburst galaxies gives useful insights on the physical processes quenching the star formation in the most massive environments. Exploiting the MUSE data of the GAs Stripping Phenomena in galaxies (GASP) project,…
The relationship between a galaxy's properties and its circumgalactic medium (CGM) provides a unique view of how galaxies evolve. We present an interesting edge-on (i=86 degrees) disk galaxy (G1547) where the CGM is probed by a background…
We analyze the angular clustering of z~2.3 distant red galaxies (DRGs) measured by Quadri et al 2008. We find that, with robust estimates of the measurement errors and realistic halo occupation distribution modeling, the measured clustering…
We use the stellar-mass-selected catalog from the Spitzer Large Area Survey with Hyper-Suprime-Cam (SPLASH) in the COSMOS field to study the environments of galaxies via galaxy density and clustering analyses up to $z \sim 2.5$. The…
A clear transition feature of galaxy quenching is identified in the multi-parameter space of stellar mass ($M_*$), bulge to total mass ratio ($B/T_{\rm m}$), halo mass ($M_{\rm h}$) and halo-centric distance ($r/r_{180}$). For given halo…
A pilot study with the powerful new backend of the Westerbork Synthesis Radio Telescope (WSRT) of two galaxy clusters at z=0.2 has revealed neutral hydrogen emission from 39 galaxies. The volume probed for each cluster is 1.7x10^4 Mpc^3,…
We study the dynamical state and properties of galaxies and groups in the supercluster SClA2142 that has a collapsing core, to understand its possible formation and evolution. We find the substructure of galaxy groups using normal mixture…
We present results on the measured shapes of 832 galaxies in 11 galaxy clusters at 1.0 < z <1.4 from the GOGREEN survey. We measure the axis ratio ($q$), the ratio of the minor to the major axis, of the cluster galaxies from near-infrared…
Low-mass quiescent galaxies are thought to predominantly reside in overdense regions, as environmental effects are often invoked to explain their shutdown of star formation. These longer-timescale quenching mechanisms - such as interactions…
We examine the outskirts of galaxy clusters in the C-EAGLE simulations to quantify the `edges' of the stellar and dark matter distribution. The radius of the steepest slope in the dark matter, commonly used as a proxy for the splashback…
Many $z=1.5$ galaxies with a stellar mass ($M_{\star}$) $\geq 10^{10}\,\mathrm{M}_\odot$ are already quenched in both galaxy clusters ($>50$ per cent) and the field ($>20$ per cent), with clusters having a higher quenched fraction at all…
We present measurements of the radial profiles of the mass and galaxy number density around Sunyaev-Zel'dovich-selected clusters using both weak lensing and galaxy counts. The clusters are selected from the Atacama Cosmology Telescope Data…
Using group catalogs from the SDSS DR7, we attempt to measure galactic conformity in the local universe. We measure the quenched fraction of neighbor galaxies around isolated primary galaxies, dividing the isolated sample into star-forming…
We have considered a phenomenologically motivated model in which galaxies are quenched when the energy output of the central black hole exceeds a hundred times the gravitational binding energy of the baryons in the host halo. The model…
The mechanisms that bring galaxies to strongly reduce their star formation activity (star-formation quenching) is still poorly understood. To better study galaxy evolution, we propose a classification based on the maps of the ionised…
We study the morphological transformation from late types to early types and the quenching of galaxies with the seventh Data Release (DR7) of the Sloan Digital Sky Survey (SDSS). Both early type galaxies and late type galaxies are found to…
While the star formation rates and morphologies of galaxies have long been known to correlate with their local environment, the process by which these correlations are generated is not well understood. Galaxy groups are thought to play an…
AIMS: We present in this work low and intermediate resolution spectroscopic data collected for 152 early type galaxies in 8 nearby clusters with z $\leq$ 0.10. METHODS: We use low resolution data to produce the redshift and the K-correction…