The Genoa Active Message MAchine (GAMMA) is an ee-cient communication layer for 100base-T clusters of Personal Computers running Linux. It is based on Active Ports, a communication mechanism derived from Active Messages. GAMMA Active Ports deliver excellent communication performance at user level (latency 12.7 s, maximum throughput 12.2 MByte/s, half-power point reached with 192 byte long messa...

The clustering properties of clusters, galaxies and AGN as a function of redshift are briefly discussed. It appears that extremely red objects at z ∼ 1, and objects with J − K > 1.7 and photometric redshifts 2 < zphot < 4 are highly clustered, indicating that a majority of these objects constitutes the progenitors of nearby ellipticals. Similarly clustered seem luminous radio galaxies at z ∼ 1,...

We present a list of z abs ∼ zem (∆v < 3000 km s −1) DLAs discovered during the CORALS survey for absorbers in a radio-selected QSO sample. On the assumption that z abs ∼ zem DLAs are neither ejecta from the QSO, nor part of the host galaxy itself, we use the number density statistics of these DLAs to investigate galaxy clustering near the QSO redshift. We find that n(z) of z abs ∼ zem DLAs in ...

We demonstrate how the properties of a galaxy depend on the mass of its host dark matter subhalo, using two independent models of galaxy formation. For the cases of stellar mass and black holemass, themedian property value displays amonotonic dependence on subhalomass. The slope of the relation changes for subhalomasses for which heating by active galactic nuclei becomes important. The median p...

We compute two-point correlation functions and measure the shear signal due to galaxy-galaxy lensing for 80 000 optically identified and 5 700 radio-loud AGN from Data Release 4 (DR4) of the Sloan Digital Sky Survey. Halo occupation models are used to estimate halo masses and satellite fractions for these two types of AGN. The large sample size allows us to separate AGN according to the stellar...

We review the current status of studies of large-scale structure in the X-ray Universe. After motivating the use X-rays for cosmological purposes, we discuss the various approaches used on different angular scales including X-ray background multipoles, cross-correlations of the X-ray background with galaxy catalogues, clustering of X-ray selected sources and small-scale fluctuations and anisotr...

We measure the angular clustering of ∼ 2000 radio sources in The Bootes Deep Field, covering 5.3 deg 2 down to S 1.4GHz = 0.2 mJy. With reference to work by Blake & Wall, we show that the size distribution of multi-component radio galaxies dominates the overall clustering signal, and that its amplitude extrapolates smoothly from their measurements above 5 mJy. The upper limits on any true galax...