We report the discovery of highly distorted X-ray emission associated with the nearby cluster Zw 1718.1–0108, one of whose dominant members is the powerful radio galaxy 3C353. This cluster has been missed by previous X-ray cluster surveys because of its low Galactic latitude (b = 19.5◦), despite its brightness in the hard X-ray band (2–10 keV flux of 1.2 × 10erg cm s). Our optical CCD image of ...

We measure the large-scale intrinsic alignments of galaxy clusters in the Sloan Digital Sky Survey (SDSS) using subsets of two cluster catalogues: 6625 clusters with 0.1 < z < 0.3 from the maxBCG cluster catalogue (7500 deg2) and 8081 clusters with 0.08 < z < 0.44 from the adaptive matched filter catalogue (6500 deg2). We search for two types of cluster alignments using pairs of clusters: the a...

Context. We present a detailed study of the X-ray properties of the galaxy cluster Abell 548b (z=0.04), using XMM-Newton data, and discuss the connection between the thermal properties and the presence of two extended relic radio sources located at the cluster periphery. Aims. We wish to analyze the dynamical state of the cluster and confirm the presence of a major merger. We will discuss the m...

The population synthesis method is used to study the possibility of explaining the appreciable fraction of the intergalactic type-Ia supernovae (SN Ia), 20 −15%, observed in galaxy clusters (Gal-Yam et al. 2003) when close white dwarf binaries merge in the cores of globular clusters. In a typical globular cluster, the number of merging double white dwarfs does not exceed ∼ 10 per year per avera...

Strong cluster eccentricity evolution for z ≤ 0.13 has appeared in a variety of observational data sets. We examine the evolution of eccentricity in simulated galaxy clusters using a variety of simulation methodologies, amplitude normalizations, and background cosmologies. We do not find find significant evolution for z < 0.1 in any of our simulation ensembles. We suggest a systematic error in ...

High-resolution (HR) N-body resimulations of 15 massive (1014–1015 M ) dark matter (DM) haloes have been combined with the hybrid galaxy formation model GALICS to study the formation and evolution of galaxies in clusters, within the framework of the hierarchical merging scenario. This paper describes the HR resimulation technique used to build the DM halo sample and discusses its reliability. N...

We present a high-resolution simulation of globular cluster formation in a galaxy merger. For the first time in such a simulation, individual star clusters are directly identified and followed on their orbits. We quantitatively compare star formation in the merger to that in the unperturbed galaxies. The merging galaxies show a strong starburst, in sharp contrast to their isolated progenitors. ...