We investigate the possibility of measuring magnetic field strength in G-band bright points through the analysis of Zeeman polarization in molecular CH lines. To this end we solve the equations of polarized radiative transfer in the G band through a standard plane-parallel model of the solar atmosphere with an imposed magnetic field and through a

The luminosity-size and mass-size distributions of galaxies out to z~3 are presented. We use very deep near-infrared images of the Hubble Deep Field-South in the Js, H, and Ks bands, taken as part of FIRES at the VLT, to follow the evolution of the optical rest-frame sizes of galaxies. For a total of 168 galaxies with Ks,AB~2×1010 h-2 Lsolar) at 2

We estimate the dust extinction laws in two intermediate-redshift galaxies. The dust in the lens galaxy of LBQS 1009-0252, which has an estimated lens redshift of zl~=0.88, appears to be similar to that of the SMC, with no significant feature at 2175 Å. Only if the lens galaxy is at a redshift of zl~=0.3, which is completely inconsistent with the

We present the results of a near-infrared imaging study of the host galaxies of 17 quasars in the redshift range 1 RLQ(host)=-27.55+/-0.12 and K>RLQ(host)=-26.83+/-0.25]. Comparison with other samples of quasar hosts at similar and lower redshift indicates that the difference in the host luminosity between RLQs and RQQs remains the same from z=2 to

Esta tesis presenta los análisis cuantitativos de espectros ópticos y UV de una muestra de estrellas supergigantes de tipo B en la Vía Láctea, M33 y NGC300, con objeto de determinar los parámetros fundamentales, así como sus composiciones químicas y comparar los resultados obtenidos con las predicciones de los modelos de evolución estelar y

High-altitude wind has been recently proposed as an important parameter to be taken into account for astronomical site selection. We present here comprehensive and reliable statistics for wind speeds at the 200 mbar (v200 hereafter) pressure level (approximately 12 km above the Canary Islands) based on long-term climate diagnostics archive and