Fast X-ray transients (FXTs) are short-lived extragalactic X-ray sources. Recent progress through multiwavelength follow-up of Einstein Probe-discovered FXTs has shown that several are related to collapsars, which can also produce $\gamma$-ray bursts (GRBs). In this paper, we investigate the nature of the FXT EP250207b. The Very Large Telescope

To explain the properties of the local galaxy population, theoretical models require active galactic nuclei (AGNs to inject energy into host galaxies, thereby expelling outflows of gas that would otherwise form stars. Observational tests of this scenario rely on determining outflow masses, which requires measuring the electron density ( $n_\mathrm{

We present cosmological constraints from Dark Energy Survey Year 3 (DES Y3) weak lensing data using persistent homology, a topological data analysis technique that tracks how features like clusters and voids evolve across density thresholds. For the first time, we apply spherical persistent homology to galaxy survey data through the algorithm

We present a detailed analysis of Terz V 2513 (=2MASS J17334728-2719266), a poorly studied symbiotic star. Our motivation was a peculiar beating pattern in its light curves from all-sky surveys and our own observations. Using Gaia DR3 and OGLE-IV photometry, we show that this variability arises from blending with a nearby, unrelated Mira variable

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

Context. The photospheric Evershed flow is normally oriented radially outward, yet sometimes opposite velocities are observed not only in the chromosphere but also in the photospheric layers of the penumbra. Aims. We studied the velocity field in a special case of an active region with two mature sunspots, the lesser of which formed several days