We analyze the structure of a small sample of galaxies, using a set of CCD images in standard photometric bands presented in a previous paper (Prieto et al. 1991). These and their combinations in the form of color index images, offer high quality information about the structure of the galaxies, allowing us to pick out the major concentrations of

The authors present preliminary results of an infrared monitoring program of selected blazars, conducted at the Carlos Sanches Telescope at Izana Observatory, Teneriffe. Eight blazars have been observed during three observing runs since August 1990. All observed blazars have shown variability.

The paper presents simultaneous monitoring of the BL Lacertae object Markarian 501 obtained in the visible and near infrared using a double photometer system on the 1.5 m Carlos Sanchez Telescope situated in El Observatorio del Teide (Tenerife) and CCD photometry in U and B taken with the 1 m Jacobus Kapteyn Telescope of El Observatorio del Roque

Not Available

Two alternative methods for evaluating the probability densities of structures defined by d degrees of freedom in random fields are presented. For Gaussian random fields, both differentiable and nondifferentiable, the application of these methods is considered in detail. The relationship between structures, maxima, and connected regions above a

Not Available