Two of us (M.M. and J.A.L.A.) imaged five galaxy clusters with the 2.5m Nordic Optical Telescope (NOT) located at the Roque de Los Muchachos Observatory (La Palma). The observations were taken with the Stand Camera, with a field of view of 3'x3', a plate scale of 0.176"/pix, a gain of 1.69e-/ADU and a readout noise of 6.36e-. All images were taken

We report the discovery in the Sloan Digital Sky Survey (SDSS) and the SDSS-III Baryon Oscillation Spectroscopic Survey of 17 broad absorption line (BAL) quasars with high-ionization troughs that include absorption redshifted relative to the quasar rest frame. The redshifted troughs extend to velocities up to v ≃ 12 000 km s-1 and the trough widths

have complex and highly structured profiles. We discuss, in the context of the discrete cloud model of the broad-line region, three possible mechanisms by which profile structure could be produced: irregularities in the radial luminosity distribution, flattened geometries and ionizing continuum variability. In each case, the structure produced has

PKS 0537-441, a bright gamma -ray emitting blazar, was observed at radio, optical, UV and X-ray frequencies during various EGRET pointings, often quasi-simultaneously. In 1995 the object was found in an intense emission state at all wavelengths. BeppoSAX observations made in 1998, non-simultaneously with exposures at other frequencies, allow us to

Brown dwarfs are objects unable to sustain hydrogen burning in their interiors. Deep surveys and large scale infrared surveys have identified a few hundred candidates free-floating in star clusters and in the solar neighborhood. Several brown dwarf companions to low-mass stars have also been detected. In the absence of a direct mass determination