Aims: We present an analysis of the 700 ks Chandra ACIS-S observation of the field around the radio galaxy J1140-2629 (the Spiderweb Galaxy) at z = 2.156, focusing on the nuclear activity in the associated large-scale environment. Methods: We identified unresolved X-ray sources in the field down to flux limits of 1.3 × 10 −16 and 3.9 × 10 −16 erg s

The C-19 stream is the most metal-poor stellar system ever discovered, with a mean metallicity [Fe/H] = -3.38 ± 0.06. Its low metallicity dispersion (σ [Fe/H] < 0.18 at the 95 per cent confidence level) and variations in sodium abundances strongly suggest a globular cluster origin. In this work, we use Very Large Telescope (VLT)/UV-Visual Echelle

We present the discovery and characterization of two transiting planets observed by TESS in the light curves of the young and bright (V = 9.67) star HD73583 (TOI-560). We perform an intensive spectroscopic and photometric space- and ground-based follow-up in order to confirm and characterize the system. We found that HD73583 is a young (~500 Myr)

Superconducting nanowire detectors fed by single mode fibres are essential to minimize dark counts in a quantum communication receiver. Efficient coupling of the received light to the single mode fibre is fundamental for the system performance, but it gets deeply affected by the atmospheric turbulence. Adaptive Optics measure and correct for the

A plenoptic wavefront sensor is proposed for the measurement of the atmospheric turbulence on satellite-toground optical communications. The design will be based on the outcome of the performance simulations for the specific site Teide Observatory (Spain). The performance of the plenoptic wavefront sensor is compared to a Shack-Hartmann wavefront

This article summarizes the results of a system engineering approach to the design of a Transportable Optical Ground Station (TOGS) intended to be used for quantum key distribution in a number of scenarios. Key requirements are listed and a product breakdown is proposed, identifying parts, which are specific to a particular scenario and others