Related papers: The offsets between galaxies and their dark matter…
We explore galaxy properties and their link with environment and clustering using a population of ~1000 galaxies formed in a high resolution hydrodynamic simulation of the Lambda CDM cosmology. At the redshift we concentrate on, z=1, the…
We report on work in progress by the Virgo consortium, a collaboration set up to carry out large simulations of the formation of galaxies and large-scale structure exploiting the latest generation of parallel supercomputers. We show results…
We test the predictions of Emergent Gravity using matter densities of relaxed, massive clusters of galaxies using observations from optical and X-ray wavebands. We improve upon previous work in this area by including the baryon mass…
In an influential recent paper, Harvey et al (2015) derive an upper limit to the self-interaction cross section of dark matter ($\sigma_{\rm DM} < 0.47$ cm$^2$/g at 95\% confidence) by averaging the dark matter-galaxy offsets in a sample of…
We present a detailed study of relaxed and unrelaxed galaxy clusters in a large dark-matter only simulation. Recent work has demonstrated clear differences between the galaxy populations in clusters which have Gaussian velocity…
We explore the mass distribution of material associated with galaxies from the observation of gravitational weak lensing for the galaxy mass correlation function with the aid of $N$-body simulations of dark matter. The latter is employed to…
Using N-body+hydro simulations we study relations between the local environments of galaxies on 0.5 Mpc scale and properties of the luminous components of galaxies. Our numerical simulations include effects of star formation and supernova…
This paper reviews some recent work on the properties of the outer halos of galaxies. I particularly focus on recent and upcoming advances made with the study of globular clusters. Globular clusters can be observed out to ~100 kpc from the…
In galaxy cluster collisions, the gas can be separated from dark matter halos. Abell~56 displays signatures of a dissociative bullet-like merger with a possible high inclination angle between the plane of orbit and the sky. Our objective is…
We examine high-resolution gravitational N-body simulations of the $\Omega=1$ cold dark matter (CDM) model in order to determine whether there is any normalization of the initial density fluctuation spectrum that yields acceptable results…
We investigate a recent claim that observed galaxy clusters produce an order of magnitude more galaxy-galaxy strong lensing (GGSL) than simulated clusters in a LCDM cosmology. We take galaxy clusters from the C-EAGLE hydrodynamical…
We calculate the colours and luminosities of redshift z = 0.1 galaxies from the EAGLE simulation suite using the GALAXEV population synthesis models. We take into account obscuration by dust in birth clouds and diffuse ISM using a…
We investigate the contentious issue of the presence, or lack thereof, of satellites mass segregation in galaxy groups using the Galaxy And Mass Assembly (GAMA) survey, the GALFORM semi-analytic and the EAGLE cosmological hydrodynamical…
We study the properties of the diffuse light in galaxy clusters forming in a large hydrodynamical cosmological simulation of the Lambda-CDM cosmology. The simulation includes a model for radiative cooling, star formation in dense cold gas,…
We present results of N-body/gasdynamical simulations designed to investigate the evolution of X-ray clusters in a flat, low-density, cold dark matter (CDM) cosmogony. The density profile of the dark matter component can be fitted rather…
We report on analyses of cluster samples obtained from the Hubble Volume Simulations. These simulations, an $\Omega=1$ model named $\tau$CDM and a flat low $\Omega$ model with a cosmological constant ($\Lambda$CDM), comprise the largest…
Current data broadly support trends of galaxy surface brightness profile amplitude and shape with total stellar mass predicted by state-of-the-art Lambda-CDM cosmological simulations, although recent results show signs of interesting…
We present new weak lensing observations of 1E0657-558 (z=0.296), a unique cluster merger, that enable a direct detection of dark matter, independent of assumptions regarding the nature of the gravitational force law. Due to the collision…
We have made mass maps of three strong-lensing clusters, Abell 3827, Abell 2218 and Abell 1689, in order to test for mass-light offsets. The technique used is GRALE, which enables lens reconstruction with minimal assumptions, and…
The gas is the dominant component of baryonic matter in most galaxy groups and clusters. The spatial offsets of gas centre from the halo centre could be an indicator of the dynamical state of cluster. Knowledge of such offsets is important…