The spectrographs on-board the World Space Observatory (WSO) will provide access to the 1020-1800 Å wavelength range with unprecedented sensitivity. Previous observatories operating in the 1150-2000 Å range (such as IUE and HST-STIS) have proved extremely useful to study the winds of OB type stars, which leave their most prominent imprints in the

Not Available

Optical instruments for measurement of precise rapid timing have recently given us the capability of going beyond X-ray variability. Observations of several sources have revealed multi-wavelength variations on a wide range of continuous timescales from ms up, and intriguing flux correlations with X-ray fluctuations have been found. These give

Following our recent report on the transition to quiescence of the transient neutron star low-mass X-ray binary XTE J1701-407 (ATel #3604), we continued to monitor the source in X-rays. Further observations were carried out between August 31 and September 20, during which Swift pointed towards the source once every 2-4 days with the XRT operated in

We present results of an extensive study of the X-ray spectral properties of sources detected in the RIXOS survey, which is a large, nearly complete sample of objects detected serendipitously in ROSAT PSPC fields down to a flux limit of 3x10^-14ergcm^-2s^-1 (0.5-2keV). We show that for X-ray surveys containing sources with low count rate, such as

Context. Variability is a general property of active galactic nuclei (AGN). The way in which these changes occur at X-rays is not yet clearly understood. In the particular case of low-ionization nuclear emission line region (LINER) nuclei, variations on the timescales from months to years have been found for some objects, but the main driver of