We present simultaneous high time resolution (1-10 Hz) X-ray and optical observations of the persistent LMXBs Sco X-l and V801 Ara( = 4 U 1636-536). In the case of Sco X-l we find that the Bowen/HeII emission lags the X-ray light-curves with a light travel time of ~11-16 s which is consistent with reprocessing in the donor star. We also present the

In this paper we give a review of the Bowen fluorescence survey, showing that narrow emission lines (mainly N III and C III lines between 4630 and 4660 A˚) appear to be universally present in the Bowen blend of optically bright low mass X-ray binaries. These narrow lines are attributed to reprocessing in the companion star giving the first

We present preliminary results from an observational campaign aimed at the study of the binary fraction and binary radial distribution in Galactic globular clusters. In particular, we concentrate on the ongoing observational campaign for the search of spectroscopic binaries.

We report on early observations of the optical afterglow of GRB 070411 obtained by the Črni Vrh 0.6-m, the ROTSE IIIc 0.45-m, and the Tautenburg 1.34-m Schmidt telescope starting within 1 to 5 minutes after the trigger. The derived light curve presents a rising phase, then a plateau followed by a steep decay and finally a jet break.

Gamma ray astronomy is now at the leading edge for studies related both to fundamental physics and astrophysics. The sensitivity of gamma detectors is limited by the huge amount of background, constituted by hadronic cosmic rays (typically two to three orders of magnitude more than the signal) and by the accidental background in the detectors. By

The determination of the galaxy merger fraction of field galaxies using automatic morphological indices and photometric redshifts is affected by several biases if observational errors are not properly treated. Here, we correct these biases using maximum likelihood techniques. The method takes into account the observational errors to statistically