Over a dozen millisecond pulsars are ablating low-mass companions in close binary systems. In the original `black widow', the eight-hour orbital period eclipsing pulsar PSR J1959+2048 (PSR B1957+20) 1, high-energy emission originating from the pulsar 2 is irradiating and may eventually destroy 3 a low-mass companion. These systems are not only

We report on a long-term optical monitoring of the neutron star X-ray binary Centaurus X-4 performed during the last 13.5 yr. This source has been in quiescence since its outburst in 1979. Our monitoring reveals the overall evolution of the accretion disk; we detect short-duration flares, likely originating also in the disk, superimposed with a

The detailed characterization of scaling laws relating the observables of a cluster of galaxies to their mass is crucial for obtaining accurate cosmological constraints with clusters. In this paper, we present a comparison between the hydrostatic and lensing mass profiles of the cluster MACS J0647.7+7015 at z = 0.59. The hydrostatic mass profile is

We present simple stellar population models based on the empirical X-shooter Spectral Library (XSL) from near-ultraviolet (NUV) to near-infrared (NIR) wavelengths. The unmatched characteristics of the relatively high resolution and extended wavelength coverage (350-2480 nm, R ∼ 10 000) of the XSL population models bring us closer to bridging