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

Stellar streams are sensitive to perturbations from, for example, giant molecular clouds, bars and spiral arms, infalling dwarf galaxies, or globular clusters which can imprint gaps, clumps, spurs, and asymmetries in tails. In addition to these effects, the impact of a major galactic merger on a population of stellar streams remains to be explored

We investigate galaxy populations in the HS 1700+64 protocluster at $z=2.30$, characterized by two prominent linear filaments traced by spatially extended ${\rm Ly} \, \alpha$ blobs. We conducted a wide area mapping of emission line galaxies across the protocluster using the unique combination of three matched narrow-band filters, corresponding to