Context. Gaia-Sausage-Enceladus is considered the last major merger that contributed to the formation of the Milky Way. Its remnants dominate the nearby accreted stellar halo of the Milky Way. Aims. We aim to characterise the star formation history of Gaia-Sausage-Enceladus through the age and metallicity of its stellar populations. Methods. From

From a parent catalog of 561 changing-look active galactic nuclei (CL-AGNs) identified by W.-J. Guo et al., we investigate the evolutionary sequence of broad emission lines using a redshift-selected subset (0.35 < z < 0.45) of 54 CL-AGNs whose Dark Energy Spectroscopic Instrument (DESI) spectra simultaneously cover the Hα, Hβ, and Mg II emission

Context. Diagnostic diagrams based on optical emission lines, especially classical BPT diagrams, have long been used to distinguish the dominant ionisation mechanisms in galaxies. However, these methods suffer from degeneracies and limitations, particularly when applied to complex systems such as galaxies, where multiple ionisation sources coexist

In this work we examine the baryon acoustic oscillations (BAO) in 2D angular and redshift space {θ, ∆z}, with ∆z denoting the redshift difference between two given angular shells. We thus work in the context of tomographic analyses of the large scale structure (LSS) where data are sliced in different redshift shells and constraints on Cosmology are

We present calibrated Asteroid Terrestrial-impact Last Alert System (ATLAS) photometry of the interstellar comet 3I/ATLAS (C/2025 N1) from March 28 through 2025 August 29, obtained with the five-site, robotic ATLAS network in the c (420─650 nm), o (560─820 nm), and Teide w (420─720 nm) bands. Stacked difference images yield reliable light curves