Context. Diagnostic diagrams based on optical emission lines, especially classical BPT diagrams, have long been used to distinguish the dominant ionisation...

Widefield surveys probe clustered scalar fields - such as galaxy counts, lensing potential, etc. - which are sensitive to different cosmological and...

The faint end of the differential galaxy number counts n(m) in the Hubble Deep Field-North (HDF-N) has been determined for the F450W, F606W, and F814W filters...

We explore unsupervised machine learning for galaxy morphology analyses using a combination of feature extraction with a vector-quantized variational...

Subgiants and early red giants are crucial for studying the first dredge-up, a key evolutionary phase in which the convective envelope deepens, mixing...

Aims. Active galactic nuclei (AGN) are typically identified through their distinctive X-ray or radio emissions, mid-infrared (MIR) colors, or emission lines...

We analyse a wealth of optical spectroscopic and photometric observations of the bright (V = 11.9) cataclysmic variable BG Tri. The Gaia DR2 parallax gives a...

Aims: We present a study of the statistical properties of three velocity dispersion and mass estimators: biweight, gapper, and standard deviation for a small...

We measure the correspondence between the distribution of galaxies and matter around troughs and peaks in the projected galaxy density, by comparing redMaGiC...