Related papers: Candidate fossil groups in the CFHTLS: a probabili…
The detection of galaxy clusters in present and future surveys enables measuring mass-to-light ratios, clustering properties or galaxy cluster abundances and therefore, constraining cosmological parameters. We present a new technique for…
Based on a recent photometric redshift galaxy catalogue, we have searched for galaxy clusters in the Stripe~82 region of the Sloan Digital Sky Survey by applying the Adami & MAzure Cluster FInder (AMACFI). Extensive tests were made to…
We determine the near-infrared Fundamental Plane (FP) for $\sim10^4$ early-type galaxies in the 6dF Galaxy Survey (6dFGS). We fit the distribution of central velocity dispersion, near-infrared surface brightness and half-light radius with a…
We examine the environment of star-forming galaxies selected in the 2dFGRS. We find that bright star-forming galaxies display a significant deficit of faint neighbours relative to passive galaxies. If a deficit in fainter companions implies…
The Cheshire Cat is a relatively poor group of galaxies dominated by two luminous elliptical galaxies surrounded by at least four arcs from gravitationally lensed background galaxies that give the system a humorous appearance. Our combined…
We present results from a systematic investigation of the X-ray properties of a sample of moderate redshift (0.3<z<0.6) galaxy groups. These groups were selected not by traditional X-ray or optical search methods, but rather by an…
We investigated the evolution of the physical properties of the brightest galaxies in clusters and their protohalos from $z = 4$ to $z = 0$. Galaxy clusters and groups are identified using a halo-based group finder applied to the COSMOS2020…
We use large cosmological N-body simulations to study the subhalo population in galaxy group sized halos. In particular, we look for fossil group candidates with typical masses ~10-25% of Virgo cluster but with an order of magnitude less…
The Frontier Fields program is obtaining deep Hubble and Spitzer Space Telescope images of new "blank" fields and nearby fields gravitationally lensed by massive galaxy clusters. The Hubble images of the lensed fields are revealing nJy…
We report ten lens candidates in the E-CDFS from the GEMS survey. Nine of the systems are new detections and only one of the candidates is a known lens system. For the most promising five systems including the known lens system, we present…
We apply a halo-based group finder to four large redshift surveys, the 2MRS, 6dFGS, SDSS and 2dFGRS, to construct group catalogs in the low-redshift Universe. The group finder is based on that of Yang et al. but with an improved halo mass…
We present results of VLT/FORS2 spectroscopy of galaxies at z~3 in the Hubble Deep Field-South (HDF-S). A sample of galaxies was drawn from the photo-z catalogue based on the HST/WFPC2 optical images and the deep near-infrared images…
We present predictions for the clustering of galaxies selected by their emission at far infra-red (FIR) and sub-millimetre wavelengths. This includes the first predictions for the effect of clustering biases induced by the coarse angular…
The discovery of the large-scale structure has transformed our view of galaxy formation and evolution. Filaments of the cosmic web provide key environments that channel the growth of structures. Guided by predictions from cosmological…
With the help of a statistical parameter derived from optical spectra, we show that the current star formation rate of a galaxy, falling into a cluster along a supercluster filament, is likely to undergo a sudden enhancement before the…
Observations of molecular clouds reveal a complex structure, with gas and dust often arranged in filamentary rather than spherical geometries. The associations of pre- and proto- stellar cores with the filaments suggest a direct link with…
Compact groups of galaxies appear to be extremely dense, making them likely sites of intense galaxy interaction, while their small populations make them relatively simple to analyze. In order to search for optical interaction tracers such…
We investigate the environments and clustering properties of starburst galaxies selected from the 2dF Galaxy Redshift Survey (2dFGRS) in order to determine which, if any, environmental factors play a role in triggering a starburst. We…
Candidate Dark Galaxy-2 (CDG-2) is a potential dark galaxy consisting of four globular clusters (GCs) in the Perseus cluster, first identified in Li et al. (2025) through a sophisticated statistical method. The method searched for…
We have exploited the new, deep, near-infrared UltraVISTA imaging of the COSMOS field, in tandem with deep optical and mid-infrared imaging, to conduct a new search for luminous galaxies at redshifts z ~ 7. The unique multi-wavelength…