The dwarf elliptical galaxies (dEs) are more luminous than dwarf spheroidals and fainter than "normal" ellipticals. In this paper I investigate the interconnection between these three families of early-type galaxies by studying their stellar populations properties. Some dwarf ellipticals have strong metallicity and age gradients, up to - 0.5 dex

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We introduce a Monte Carlo ray tracing code for soft X-ray fluorescence in particulate media. We use the code to investigate the observation geometry dependent effects on absolute fluorescence line intensities and relative line ratios due to the medium porosity, incident spectrum, and particle size distribution. In particular, we assess the

A review of the ability of asteroseismology to probe the internal physics of OB stars is presented. The main constraints that can be obtained from the frequency spectrum in p- and g-modes pulsators are discussed. Next, we consider energetic aspects of the pulsations in OB stars and show how such study also allows to constrain their internal physics

It has been suggested that the outer young Galactic halo globular cluster population might be associated (or even the nuclei) to tidal disrupted dwarf spheroidals, now extinct galaxies. If this hypothesis is true, these systems might be still surrounded by a distinct and detectable stellar population similar to that of their progenitor galaxies. We

We compare the Hubble type and the spectroscopic class of the galaxies with spectra in the Sloan Digital Sky Survey Data Release 7. As has long been known, elliptical galaxies tend to be red whereas spiral galaxies tend to be blue; however, this relationship presents a large scatter, which we measure and quantify in detail for the first time. We