Related papers: On the [$\alpha$/Fe]-[Fe/H] relations in early-typ…
We use the spectra of ~ 22,000 early-type galaxies, selected from the Sloan Digital Sky Survey, to infer the ages, metallicities and star formation histories of these galaxies. We find clear evidence of "downsizing", i.e. galaxies with…
CONTEXT: [ABRIDGED]. For the Milky Way bulge, there are currently essentially no measurements of carbon in un-evolved stars, hampering our abilities to properly compare Galactic chemical evolution models to observational data for this still…
The optical morphology of galaxies is strongly related to galactic environment, with the fraction of early-type galaxies increasing with local galaxy density. In this work we present the first analysis of the galaxy morphology-density…
We present gas-phase elemental abundance ratios of 7 local extremely metal-poor galaxies (EMPGs) including our new Keck/LRIS spectroscopy determinations together with 33 JWST $z\sim 4-10$ star-forming galaxies in the literature, and compare…
A simple model of chemical enrichment in cluster early-type galaxies is presented where the main parameters driving the formation of the stellar component are reduced to four: infall timescale (tf), formation epoch (zF), star formation…
We present results of a detailed chemical analysis performed on 23 main-sequence turnoff stars having -3.4<=[Fe/H]<=-2.2, a sample selected to be highly homogeneous in T_eff and log(g). We investigate the efficiency of mixing in the early…
The aim of the present paper is to quantify the dependence of the estimates of luminosities and stellar mass of early-type galaxies on the different models and model parameters which can be used to analyze the observational data. The paper…
Using a new numerical model for cosmic chemical evolution, we study the influence of hypernova feedback on the star formation and metal enrichment history of the universe. For assumptions which produce plausible results in idealized…
We present models that predict spectra of old- and intermediate-aged stellar populations at 2.51\AA\ (FWHM) with varying [\alpha/Fe] abundance. The models are based on the MILES library and on corrections from theoretical stellar spectra.…
In a sample of elliptical galaxies that span a large range of mass, a previously unused Ca index, CaHK, shows that [Ca/Fe] and [Ca/Mg] systematically decrease with increasing elliptical galaxy mass. Metallicity mixtures, age effects,…
We have extended our H alpha objective prism survey of 8 low-redshift clusters (viz. Abell 262, 347, 400, 426, 569, 779, 1367 and 1656) to include a complete sample of early-type galaxies within 1.5 Abell radii of the cluster centres. Of…
Recent observations by the James Webb Space Telescope (JWST) have found evidence for an invariant relation between stellar mass, metallicity, and star formation rate up to $z\sim 8$ and its breakdown at higher redshifts. Understanding the…
Context: The chemical composition of stars is intimately linked to the Galaxy formation and evolution. Aims: We aim to trace the chemical evolution of the Galactic disk through the inspection of the [X/Fe]-age relations of 24 species from C…
We perform a suite of cosmological hydrodynamical simulations of disc galaxies, with zoomed-in initial conditions leading to the formation of a halo of mass $M_{\rm halo, \, DM} \simeq 2 \cdot 10^{12}$ M$_{\odot}$ at redshift $z=0$. These…
We explore the relationships between the chemistry, ages, and locations of stars in the Galaxy using asteroseismic data from the K2 mission and spectroscopic data from the Apache Point Galactic Evolution Experiment survey. Previous studies…
We studied the radio properties of very young massive regions of star formation in HII galaxies, with the aim of detecting episodes of recent star formation in an early phase of evolution where the first supernovae start to appear. Our…
Galactic chemical evolution models which include sodium from type II supernovae alone underestimate the abundance of sodium in the interstellar medium by a factor of two to three over about 3 dex in metallicity and predict a flat behaviour…
Galaxy formation models are now able to reproduce observed relations such as the relation between galaxies' star formation rates (SFRs) and stellar masses ($M_*$) and the stellar mass--halo mass relation. We demonstrate that comparisons of…
New information on the relations between the Galactic disks, the halo, and satellite galaxies is being obtained from elemental abundances of stars having metallicities in the range -1.5 < [Fe/H] < -0.5. The first results for a sample of 26…
We present a newly observed relation between galaxy mass and radial metallicity gradients of early-type galaxies. Our sample of 51 early-type galaxies encompasses a comprehensive mass range from dwarf to brightest cluster galaxies. The…