We use semi-analytical methods to obtain detailed chemical evolution models (CEMs) for the dwarf spheroidal (dSph) galaxy Tucana. Published star formation rates and the age-metallicity relationship are used to constrain the observables. The results show that Tucana: (i) behaved like a closed box for 75 per cent of its life, (ii) had either a

MAXI J1659-152 is a 2.4 h orbital period X-ray dipping transient black hole candidate. We present spectroscopy of its I ≍ 23 quiescent counterpart, where we detect Hα emission with full width half maximum (FWHM) of 3200 ± 300 km s -1. Applying the correlation between the Hα FWHM and radial velocity semi-amplitude of the donor star for quiescent X

We introduce a new software package for modelling the point spread function (PSF) of astronomical images, called PIFF (PSFs In the Full FOV), which we apply to the first three years (known as Y3) of the Dark Energy Survey (DES) data. We describe the relevant details about the algorithms used by PIFF to model the PSF, including how the PSF model

We investigate potential gains in cosmological constraints from the combination of galaxy clustering and galaxy-galaxy lensing by optimizing the lens galaxy sample selection using information from Dark Energy Survey (DES) Year 3 data and assuming the DES Year 1 METACALIBRATION sample for the sources. We explore easily reproducible selections based

We perform a joint analysis of the counts of redMaPPer clusters selected from the Dark Energy Survey (DES) year 1 data and multiwavelength follow-up data collected within the 2500 deg 2 South Pole Telescope (SPT) Sunyaev-Zel'dovich (SZ) survey. The SPT follow-up data, calibrating the richness-mass relation of the optically selected redMaPPer

We study structural properties of spectroscopically confirmed massive quiescent galaxies at z ≍ 3 with one of the first sizeable samples of such sources, made of ten 10.8 < log (M ⋆/M ☉) < 11.3 galaxies at 2.4 < z < 3.2 in the COSMOS field whose redshifts and quiescence are confirmed by Hubble Space Telescope (HST) grism spectroscopy. Although