We report a direct comparison of the amplitudes of Stokes spectra of the Fe i 630 nm and 1.56 μm lines produced by realistic MHD simulations with simultaneous observations in the same spectral regions. The Stokes spectra were synthesized in snapshots with a mixed polarity magnetic field having a spatially averaged strength, B >, between 10 and 30

We analyze multiwavelength observations of the cancellation of a moving magnetic feature and a plage element at the outer edge of the moat of an isolated, round sunspot. The event lasted for some 35 minutes until the smaller flux concentration disappeared completely from the photosphere. The data set consists of high-resolution, full vector

Planetary nebulae (PNe) in the Magellanic Clouds (LMC, SMC) offer a unique opportunity to study both the population and evolution of low- and intermediate-mass stars in an environment which is free of the distance scale bias that hinder Galactic PN studies. At the same time, LMC and SMC PNe cover a wide metallicity baseline. Their progenitors might

We have investigated the properties of the diffuse light in the Virgo Cluster core region, based on the detection of intracluster planetary nebulae (PNs) in four fields. We eliminate the bias from misclassified faint continuum objects, using improved Monte Carlo simulations, and the contaminations by high-redshift Lyα galaxies, using the Lyα

We present a study of outflow (OF) and broad absorption line (BAL) systems in Mrk 231, and in similar infrared (IR) quasi-stellar objects (QSOs). This study is based mainly on one-dimensional and two-dimensional spectroscopy (obtained at La Palma/William Herschel Telescope, Hubble Space Telescope, International Ultraviolet Explorer, European

Los starbursts son eventos en los que se forman más de de 10e4 Msol de estrellas a un elevado ritmo en un área muy pequeña. La consecuencia final de algunos starbursts es la expulsión de todo el material procesado hacia fuera de la galaxia por medio de los llamados supervientos galácticos (SVG). En esta tesis se estudian tres casos de galaxias