We are living a renaissance of radio survey work: the size of source catalogues published in the first two years of this decade exceeds that of the entire 1980s! The total number of published flux densities in mid-1992 is probably nearing ~700,000 and is estimated to grow by a factor of four by the end of the decade. The number of known optical

This paper shows the different design concepts and techniques employed in the structural and thermal analysis of EMIR (Espectrografo Multiobjeto Infrarrojo), nowadays under development at the Instituto de Astrofisica de Canarias.

We present near-infrared imaging of a sample of 57 relatively large, northern spiral galaxies with low inclination. After describing the selection criteria and some of the basic properties of the sample, we give a detailed description of the data collection and reduction procedures. The Ksλ= 2.2-μm images cover most of the disc for all galaxies

We analyse the stellar content of almost 300deg^2 of the sky close to the Galactic plane by directly comparing the predictions of the SKY model (Cohen and Wainscoat et al.) with star counts taken from the Two Micron Galactic plane Survey (TMGS: Garzón et al.). Through these comparisons we can examine discrepancies between counts and model and

11 years of low degree helioseismic data collected by the IRIS++ network (International Research of the Interior of the Sun) have been analyzed. The epoch covered (mid-1989 to end-1999) spans the maximum and the falling phase of solar cycle 22 and the rising phase of the current solar cycle 23. Annual timeseries with an overlap of 6 months are used

Context. To understand the formation and evolution of galaxies, it is important to have a full comprehension of the role played by metallicity, star formation rate (SFR), morphology, and color. The interplay of these parameters at different redshifts will substantially affect the evolution of galaxies and, as a consequence, their evolution provides