We describe the 2023 release of the spectral synthesis code Cloudy. Since the previous
major release, migrations of our online services motivated us to adopt git as our version …

Context. The chemical composition of the Sun is a fundamental yardstick in astronomy,
relative to which essentially all cosmic objects are referenced. As such, having accurate …

We present a first study based on the analysis of the DEep Spectra of Ionized REgions Data
base (DESIRED). This is a compilation of 190 high signal-to-noise ratio optical spectra of …

Iron is one of the most important elements in-stellar astrophysics. However, spectroscopic
measurements of its abundance are prone to systematic modelling errors. We present three …

The dispersion in chemical abundances provides a very strong constraint on the processes
that drive the chemical enrichment of galaxies. Due to its proximity, the spiral galaxy M33 …

ABSTRACT A non-local-thermodynamic-equilibrium level population model of the first and
second ionization stages of iron, nickel, and cobalt is used to fit a sample of XShooter …

Understanding the Fe II emission from active galactic nuclei (AGNs) has been a grand
challenge for many decades. The rewards from understanding the AGN spectra would be …

The complexity of the energy levels in Fe ii has made it difficult to theoretically interpret its
observational emission spectrum. However, addressing this challenge could provide …

Our ability to model the shapes and strengths of iron lines in the solar spectrum is a critical
test of the accuracy of the solar iron abundance, which sets the absolute zero-point of all …

Context. In stars, metallicity is usually traced using Fe, while in nebulae, O serves as the
preferred proxy. Both elements have different nucleosynthetic origins and are not directly …