Related papers: Chemical clocks for early-type galaxies
At redshift z = 2, when the Universe was just three billion years old, half of the most massive galaxies were extremely compact and had already exhausted their fuel for star formation(1-4). It is believed that they were formed in intense…
We explore the mass-assembly and chemical enrichment histories of star forming galaxies by applying a population synthesis method to a sample of 84828 galaxies from the Sloan Digital Sky Survey Data Release 5. Our method decomposes the…
The stellar populations of intermediate-redshift galaxies can shed light onto the growth of massive galaxies in the last 8 billion years. We perform deep, multi-object rest-frame optical spectroscopy with IMACS/Magellan of ~70 galaxies in…
We measured $^{35}$Cl abundances in 52 M giants with metallicities between -0.5 $<$ [Fe/H] $<$ 0.12. Abundances and atmospheric parameters were derived using infrared spectra from CSHELL on the IRTF and from optical echelle spectra. We…
We study the evolution of $L_{*}$ elliptical galaxies in the color-magnitude diagram in terms of their star-formation history and environment, in an attempt to learn about their quenching process. We have visually extracted 1109 $L_{*}$…
We explore possible correlations between light profile shapes, as parameterized by the Sersic index or the concentration index C_re(1/3), and relevant stellar population parameters in early-type galaxies. Mean luminosity weighted ages,…
We reconstruct the history of the cosmic star formation in the universe by means of detailed chemical evolution models for galaxies of different morphological types. We consider a picture of coeval, non-interacting evolving galaxies where…
A catalog compiling the parameters of 346 open clusters, including their metallicities, positions, ages, and velocities has been composed. The elements of the Galactic orbits for 272 of the clusters have been calculated. Spectroscopic…
We derive the stellar population parameters of 11 quiescent ultra-diffuse galaxies (UDGs) from Keck/KCWI data. We supplement these with 14 literature UDGs, creating the largest spectroscopic sample of UDGs to date (25). We find a strong…
We compare the stellar population properties in the central regions of visually classified non-starforming spiral and elliptical galaxies from Galaxy Zoo and SDSS DR7. The galaxies lie in the redshift range $0.04<z<0.1$ and have stellar…
The population of compact massive galaxies observed at z > 1 are hypothesised, both observationally and in simulations, to be merger remnants of gas-rich disc galaxies. To probe such a scenario we analyse a sample of 12 gas-rich and active…
We present a study of the color evolution of elliptical and S0 galaxies in six clusters of galaxies inside the redshift range 0.78 < z < 1.27. For each cluster, we used imaging from the Hubble Space Telescope to determine morphological…
Cluster ellipticals are often thought to be among the oldest galaxies in the universe, with the bulk of their stellar mass formed at early cosmic epochs. I review recent observations of color evolution in early-type cluster galaxies at high…
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…
The ``MORPHS'' group has completed the cataloging, parameterization, and morphological classification of ~2000 galaxies in 10 rich clusters from 0.36 < z < 0.56. From a weak lensing analysis using these data, which compares the X-ray…
We have studied a sample of 89 very isolated, elliptical galaxies at z < 0.08 and compared their properties with elliptical galaxies located in a high-density environment such as the Coma supercluster. Our aim is to probe the role of…
The age of the Universe has been increasingly constrained by different techniques such as the observations of type Ia supernovae at high redshift or dating the stellar populations of globular clusters. In this paper we present a…
We study the metallicities and abundance ratios of early-type galaxies in cosmological semi-analytic models (SAMs) within the hierarchical galaxy formation paradigm. To achieve this we implemented a detailed galactic chemical evolution…
An introduction is given to projects investigating galaxy evolution quantitatively by spectroscopic observations of very distant galaxies that have weak apparent brightnesses and small sizes as it is feasible with 10m-class telescopes like…
The most massive galaxies in the present-day Universe are found to lie in the centres of rich clusters. They have old, coeval stellar populations suggesting that the bulk of their stars must have formed at early epochs in spectacular…