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Strong gravitational lenses are now being routinely discovered in wide-field surveys at (sub-)millimeter wavelengths. We present Submillimeter Array (SMA) high-spatial resolution imaging and Gemini-South and Multiple Mirror Telescope optical spectroscopy of strong lens candidates discovered in the two widest extragalactic surveys conducted by the

The image blurring by the Earth's atmosphere generally poses a substantial limitation to ground-based observations. While opportunities in space are scarce, lucky imaging can correct over a much larger patch of sky and with much fainter reference stars. We propose the first of a new kind of versatile instruments, "GravityCam", composed of ~100

We report optical and near-infrared follow-up observations of GRB 011121 collected predominantly at ESO telescopes in Chile. We discover a break in the afterglow light curve after 1.3 days, which implies an initial jet opening angle of about 9°. The jet origin of this break is supported by the fact that the spectral energy distribution is

The association of Gamma-Ray Bursts (GRBs) with Supernovae (SNe), or at least of some GRBs with some SN is now confirmed for several events. Of these, the most intense and better followed is the one associated with SN2003dh, namely GRB 030329, detected by HETE-2, a NASA ``explorer'' mission devoted to fast detection and localization of GRBs. Other

Aims.We present multiwavelength observations of the gamma-ray burst GRB 051028 detected by HETE-2 in order to derive its afterglow emission parameters and to determine the reason for its optical faintness when compared to other events. Methods: .Observations were taken in the optical (2.0 m Himalayan Chandra Telescope, 1.34 m Tautenburg, 4.2 m