Context. Blue supergiants (BSGs) are key objects for understanding the evolution of massive stars, which play a crucial role in the evolution of galaxies. However, discrepancies between theoretical predictions and empirical observations have opened up important questions yet to be answered. Studying statistically significant and unbiased samples of

Accurate modeling of galaxy distributions is paramount for cosmological analysis using galaxy redshift surveys. However, this endeavor is often hindered by the computational complexity of resolving the dark matter halos that host these galaxies. To address this challenge, we propose the development of effective assembly bias models down to small

To deepen our knowledge of the early history of the Milky Way, it is of particular interest to investigate the orbital and chemical properties of the most metal-poor stars, which are commonly associated with the oldest stars in our Universe. With the advent of astrometric (Gaia), spectroscopic (APOGEE, GALAH, LAMOST, Gaia-RVS), and photometric

The environment of galaxies plays a key role in their evolution. The availability of large extragalactic surveys makes it possible to place a galaxy not only in its immediate environment, but also in its position within the large-scale structure of the universe. Within this context, we investigate how the local environment influences the star

The residuals of the distance moduli of Type Ia supernovae (SNe Ia) relative to a Hubble diagram fit contain information about the inhomogeneity of the Universe, due to weak lensing magnification by foreground matter. By correlating the residuals of the Dark Energy Survey Year 5 SN Ia sample (DES-SN5YR) with extragalactic foregrounds from the DES

Aims: We provide an in-depth analysis of the COSMOS-Web ring, an Einstein ring at z ≈ 2 that we serendipitously discovered during the data reduction of the COSMOS-Web survey and that could be the most distant lens discovered to date. Methods: We extracted the visible and near-infrared photometry of the source and the lens from more than 25 bands