We develop a methodology to optimize the measurement of baryon acoustic oscillation (BAO) from a given galaxy sample. In our previous work, we demonstrated that one can measure BAO from tracers in underdense regions (voids). In this study, we combine the overdense and underdense tracers (galaxies and voids) to obtain better constraints on the BAO

Using deep color magnitude diagrams from HST ACS imaging, we have derived detailed star formation and chemical enrichment histories of a representative sample of six M31 dwarf spheroidal (dSph) companions in order to compare directly the timing, duration, and strength of their first episodes of star formation to those of Milky Way dSph satellites

The cosmic infrared background (CIB) provides a fundamental observational constraint on the star formation history of galaxies over cosmic history. We estimate the contribution to the CIB from catalogued galaxies in the COSMOS field by using a novel map fitting technique on the Herschel SPIRE maps. Prior galaxy positions are obtained using

Gaia16aye was a binary microlensing event discovered in the direction towards the northern Galactic disc and was one of the first microlensing events detected and alerted to by the Gaia space mission. Its light curve exhibited five distinct brightening episodes, reaching up to I = 12 mag, and it was covered in great detail with almost 25 000 data

We present high time resolution optical photometric data of the polar VV Puppis obtained simultaneously in three filters (u', HeII λ4686, r') with the ULTRACAM camera mounted at the ESO-VLT telescope. An analysis of a long 50 ks XMM-Newton observation of the source, retrieved from the database, is also provided. Quasi-periodic oscillations (QPOs)

Context. The vast majority of the known stars of ultra low metallicity ([Fe/H] < -4.5) are known to be enhanced in carbon, and belong to the "low-carbon band" (A(C) = log(C/H)+12 ≤ 7.6). It is generally, although not universally, accepted that this peculiar chemical composition reflects the chemical composition of the gas cloud out of which these