Sardinia Radio Telescope observations of Abell 194

Hard X - ray and radio observations of Abell 754

We present a long BeppoSAX observation of Abell 754 that reports a nonthermal excess with respect to the thermal emission at energies greater than ∼ 45 keV. A VLA radio observation at 1.4 GHz definitely confirms the existence of diffuse radio emission in the central region of the cluster, previously suggested by images at 74 and 330 MHz (Kassim et al. 2001), and reports additional features. Bes...

The Sardinia Radio Telescope ( SRT ) Science and Technical Requirements Report of the SRT Working Group IRA

Spitzer observations of Abell 1763

Context. The study of galaxy luminosity functions (LFs) in different environments provides powerful constraints on the physics of galaxy evolution. The infrared (IR) LF is a particularly useful tool since it is directly related to the distribution of galaxy star-formation rates (SFRs). Aims. We aim to determine the galaxy IR LF as a function of the environment in a supercluster at redshift 0.23...

Measuring the Hubble Constant from Ryle Telescope and X - ray observations , with application to Abell 1413

We describe our algorithm for measuring the Hubble constant from Ryle Telescope (RT) interferometric observations of the Sunyaev-Zel’dovich (SZ) effect from a galaxy cluster and observation of the cluster X-ray emission. We analyse the error budget in this method: as well as radio and X-ray random errors, we consider the effects of clumping and temperature differences in the cluster gas, of the...

Chandra observations of Abell 2199

We present results from an analysis of two Chandra observations of the rich, nearby galaxy cluster Abell 2199. We find evidence (having corrected for projection effects) for radial gradients in temperature and metallicity in the X-ray emitting gas: the temperature drops from kT ∼ 4.2 keV at R=200 kpc to 1.6 keV within R=5 kpc of the centre. The metallicity rises from ∼ 0.3 solar at R=200 kpc to...