We report on Chandra ACIS-S observations of five type I X-ray bursters with low persistent emission: SAX J1324.5-6313, SAX J1752.3-3128, SAX J1752.3-3128I, SAX J1324.5-6313V, and SAX J1818.7+1424. We designate candidate persistent sources for four X-ray bursters. All candidates are detected at a persistent luminosity level of 1032-33 erg s-1

In an ongoing effort to study the formation and evolution of galactic bulges, we have investigated the position of 19 bulges of type S0-Sbc on the Fundamental Plane (FP). We find that bulges, in both B and K band, lie close to but slightly below the FP defined by ellipticals and S0s, i.e. are slightly brighter. There are hints that bulges of later

PKS 0537-441, a bright gamma -ray emitting blazar, was observed at radio, optical, UV and X-ray frequencies during various EGRET pointings, often quasi-simultaneously. In 1995 the object was found in an intense emission state at all wavelengths. BeppoSAX observations made in 1998, non-simultaneously with exposures at other frequencies, allow us to

We have discovered three certain (SAX J1324.5-6313, 2S 1711-339 and SAX J1828.5-1037) and two likely (SAX J1818.7+1424 and SAX J2224.9+5421) new thermonuclear X-ray burst sources with the BeppoSAX Wide Field Cameras, and observed a second burst ever from a sixth one (2S 0918-549). Four of them (excluding 2S 1711-339 and 2S 0918-549) are newly

Esta tesis forma parte de un proyecto a largo plazo cuyo objetivo es estudiar la evolución de los parámetros estructurales de las galaxias en función de su desplazamiento al rojo y en relación a la densidad local que las rodea. La meta principal de esta tesis ha sido desarrollar un software de análisis morfológico capaz de extraer información

10199 Chariklo is the largest Centaur so far known. To investigate its surface composition and possible surface variations, spectroscopic observations have been carried out at the largest available telescopes. We obtained near-infrared spectra at ESO-VLT (Cerro Paranal, Chile) and TNG (La Palma, Spain) on April 2001 and March 2002, respectively