Related papers: [Mg/Fe] and variable initial mass function: Revisi…

We discuss chemical enrichments of ~4000 SDSS early-type galaxies using as tracers the element abundance ratios [C/Fe], [N/Fe], [O/Fe], [Mg/Fe], [Ca/Fe] and [Ti/Fe]. We utilise the stellar population models of absorption line indices from…

The measured star-formation rates (SFRs) of galaxies comprise an important constraint on galaxy evolution and also on their cosmological boundary conditions. Any available tracer of the SFR depends on the shape of the mass-distribution of…

We investigate the Mg-sigma and <Fe>-sigma relations in a sample of 72 early-type galaxies drawn mostly from cluster and group environments using a homogeneous data-set which is well-calibrated onto the Lick/IDS system. The small intrinsic…

Abundances for alpha-elements and Fe in about 150 field subdwarfs and early subgiants with accurate parallaxes and kinematic data are used to discuss the run of abundance ratios in metal-poor stars in the solar neighborhood. Based on…

Although evidence is accumulating that abundance ratios in galaxies are often non-solar, they are far from understood. I resume the current evidence for non-solar abundance ratios, supplementing the recent review by Worthey (1998) with some…

Long-slit spectra have been obtained with the Keck telescope for a sample of 11 early-type galaxies covering a wide range in luminosity and hence mass. Rotation velocity and velocity dispersions, together with 19 Lick line-strength…

Recent results form the James Webb Space Telescope (JWST) report space densities for bright and massive galaxies at z>7 that far exceed expectations of theoretical models of galaxy formation, prompting a revision of our understanding of the…

We have obtained [Mg/Fe] measurements for 76.3% of the stars in the MILES spectral library used for understanding stellar atmospheres and stellar populations in galaxies and star clusters. These abundance ratios were obtained through (1) a…

We present a comparison between the [Ca,C,N/Fe]-mass relations observed in local spheroids and the results of a chemical evolution model which already successfully reproduces the [Mg/Fe]-mass and the [Fe/H]-mass relations in these systems.…

Ultra diffuse galaxies are a population of extended galaxies but with relatively low luminosities. The origin of these objects remains unclear, largely due to the observational challenges of the low surface brightness Universe. We present…

Standard analytical chemical evolution modelling of galaxies has been assuming the stellar initial mass function (IMF) to be invariant and fully sampled allowing fractions of massive stars to contribute even in dwarf galaxies with very low…

We investigated a volume-limited sample of LAMOST main-sequence stars with masses from 0.25 to 1 $M_{\odot}$ and distances of 150-350 pc to explore how the stellar initial mass function (IMF) varies with metallicity. We corrected the…

It has frequently been suggested that the stellar IMF in galaxies was top-heavy at early times. This would be plausible physically if the IMF depends on a mass scale such as the Jeans mass that was higher at earlier times because of the…

The first stars fundamentally transformed the early Universe through their production of energetic radiation and the first heavy chemical elements. The impact on cosmic evolution sensitively depends on their initial mass function (IMF),…

The evolution of the galaxy stellar mass--star formation rate relationship (M*-SFR) provides key constraints on the stellar mass assembly histories of galaxies. For star-forming galaxies, M*-SFR is observed to be fairly tight with a slope…

We study the origin of iron and alpha-elements (O, Mg, Si) in clusters of galaxies. In particular, we discuss the [O/Fe] ratio and the iron mass-to-luminosity ratio in the intracluster medium (ICM) and their link to the chemical and…

The heavyweight stellar initial mass function (IMF) observed in the cores of massive early-type galaxies (ETGs) has been linked to formation of their cores in an initial swiftly-quenched rapid starburst. However, the outskirts of ETGs are…

The metallicity distribution function (MDF) of the Galactic bulge features a multi-peak shape, with a metal-poor peak at [Fe/H]=-0.3 dex and a metal-rich peak at [Fe/H]=+0.3 dex. This bimodality is also seen in [alpha/Fe] versus [Fe/H]…

I present a comparison between published dynamical (ATLAS3D) and spectroscopic (Conroy & van Dokkum) constraints on the stellar initial mass function (IMF) in early-type galaxies, using the 34 galaxies in common between the two works. Both…

We investigated the stellar population properties of a sample of 1858 massive compact galaxies (MCGs) extracted from the SDSS survey. Motivated by previous results showing that older compact galaxies tend to have larger velocity dispersion…