Related papers: Galaxy evolution in Abell 85: I. Cluster substruct…
Several claims have been made that we are located in a locally underdense region of the Universe based on observations of supernovae and galaxy density distributions. Two recent studies of K-band galaxy surveys have provided new support for…
We report the discovery of a population of nearby, blue early-type galaxies with high star formation rates (0.5 < SFR < 50 Msun/yr). They are identified by their visual morphology as provided by Galaxy Zoo for SDSS DR6 and their u-r colour.…
An extensive redshift survey has been conducted on a sample of 15 nearby (0.01 < z < 0.05) clusters of galaxies. A total number of 860 redshifts were determined by fitting of emission--lines and/or cross-correlation techniques. Of this…
A critical issue in studying the evolution of galaxy clusters is to find ways that enable meaningful comparisons of clusters observed at different redshifts, as well as in various stages of their growth. Studies in the past have typically…
We employ spectroscopic and photometric data from SDSS DR7, in a 500 sq degree region, to understand the evolution of dwarf (~M*+2<M_z<M*+4) galaxies in the Coma supercluster (z=0.023). We show that in the Coma supercluster, the red dwarfs…
Summary - By using the data from the ESO Nearby Abell Cluster Survey (ENACS), we have studied the properties of emission-line galaxies (ELG) in clusters. The fraction of ELG in clusters is 16~\%; this fraction is slightly dependent on the…
We present an update of our compilation of measured redshifts of galaxy clusters in the all-sky Abell catalog. In the last 7 years the number of ACO clusters with measured z has doubled to now ~2100, but still ~56% of these are based on…
Extended, steep, and ultra-steep spectrum radio emission in a galaxy cluster is usually associated with recent mergers. Simulations show that radio phoenixes are aged radio galaxy lobes whose emission reactivates when a low Mach shock…
This paper presents four color narrow-band photometry of clusters A115 ($z=0.191$) and A2283 ($z=0.182$) in order to follow the star formation history of various galaxy types. Although located at similar redshifts, the two clusters display…
Abell 383 is a famous rich cluster (z = 0.1887) imaged extensively as a basis for intensive strong and weak lensing studies. Nonetheless there are few spectroscopic observations. We enable dynamical analyses by measuring 2360 new redshifts…
We examine the inner mass distribution of the relaxed galaxy cluster Abell 383 in deep 16-band HST/ACS+WFC3 imaging taken as part of the CLASH multi-cycle treasury program. Our program is designed to study the dark matter distribution in 25…
The intracluster plasma of Abell 2052 exhibits in X-rays a spiral structure extending more than 250 kpc, which is comprised of cool gas. This feature is understood to be the result of gas sloshing caused by the off-axis collision with a…
We consider a sample of about 50 distant galaxy clusters at z>0.15 (<z> about 0.3), each cluster having at least 10 galaxies with available redshift in the literature. We select member galaxies, analyze the velocity dispersion profiles, and…
We present the results from a survey of 57 low-redshift Abell galaxy clusters to study the radial dependence of the luminosity function (LF). The dynamical radius of each cluster, r200, was estimated from the photometric measurement of…
We have examined the spatial distribution of substructure in clusters of galaxies using Einstein X-ray observations. Subclusters are found to have a markedly anisotropic distribution that reflects the surrounding matter distribution on…
We present indications, based on a sample of 303 Abell clusters, for a relation between the dynamical state of clusters and the alignments of galaxy members with their parent cluster major axis orientation as well as with the large scale…
We have measured the surface density of galaxies toward 14 X-ray-selected cluster candidates at redshifts greater than z=0.46, and we show that they are associated with rich galaxy concentrations. We find that the clusters range between…
We present environmental dependence of dusty star forming activity in and around the cluster RXJ1716.4+6708 at z=0.81 based on wide-field and multi-wavelength observations with Suprime-Cam on the Subaru telescope and IRC onboard the AKARI…
We present 4.5 {\mu}m luminosity functions for galaxies identified in 178 candidate galaxy clusters at 1.3 < z < 3.2. The clusters were identified as Spitzer/IRAC color-selected overdensities in the Clusters Around Radio-Loud AGN (CARLA)…
We present a novel method to estimate accurate redshifts of star-forming galaxies by measuring the flux ratio of the same emission line observed through two adjacent narrow-band filters. We apply this method to our NB912 and new NB921 data…