相关论文: Age-luminosity relations for low-mass metal-poor s…
Observations of Young Star Cluster ({\bf YSC}) systems in interacting galaxies are reviewed with particular emphasis on their Luminosity Functions ({\bf LF}) and colour distributions. A few spectroscopic abundance measurements are…
Ancient, long-lived stars remain present in all components of our home galaxy, the Milky Way. Born a few hundred million after the Big Bang and during a time that marked the very beginning of the chemical evolution, these stars display very…
The correlation between [Mg/Fe] and galaxy mass found in elliptical galaxies sets a strong constraint on the duration of star formation. Furthermore, the colour-magnitude relation restricts the range of ages and metallicities of the stellar…
We determined the ages, the kinematic parameters and Galactic orbital parameters of six metal-poor (-2.4<[Fe/H]<-1 dex) F-type high proper motion (HPM) stars to investigate their HPM nature and origin. For the kinematical procedure, the…
The massive First Stars (the first ones to contribute to the chemical enrichment of the Universe due to their short lifetimes) are long dead, and even though efforts to directly observe them in high redshift galaxies are underway, a step…
We present accurate relative ages for a sample of 55 Galactic globular clusters. The ages have been obtained by measuring the difference between the horizontal branch and the turnoff in two, internally photometrically homogeneous databases.…
The knowledge of stellar ages directly impacts the characterization of a planetary system as it puts strong constraints on the moment when the system was born. Unfortunately, the determination of precise stellar ages is a very difficult…
[...] The aim of this paper is to study the precision and theoretical biases in the age determinations of halo stars adopting both asteroseismic and classic observational constraints. [...] We adopt the well-tested SCEPtER pipeline,…
Low-mass galaxies in nearby clusters are the most numerous galaxy type in the universe, yet their origin and properties remain largely unknown. To study basic questions concerning these galaxies we present the results of a survey designed…
We construct mock galaxy catalogues to analyse clustering properties of a Lambda cold dark matter (LCDM) universe within a cosmological dark matter simulation of sufficient resolution to resolve structure down to the scale of dwarfs. We…
We investigate the radial metallicity gradients and azimuthal metallicity distributions on the Galactocentric $X$--$Y$ plane using mono-temperature stellar populations selected from LAMOST MRS young stellar sample. The estimated radial…
We present unified chemical and spectrophotometric evolutionary synthesis models that allow to describe composite stellar populations in a chemically consistent way. Keeping track of the ISM abundance at birth of each star and using sets of…
Ages have been derived for 55 globular clusters (GCs) from overlays of isochrones onto the turnoff photometry, assuming distances based on fits of zero-age horizontal branch (ZAHB) models to the lower bound of the observed distributions of…
We explore the nature of the evolution of faint field galaxies by assuming that the local luminosity function is not well defined. We use a non-negative least squares technique to derive a near optimal set of local luminosity functions for…
We discuss the existence of a mass-metallicity relation among galactic halo globular clusters. The lack of any luminosity-metallicity correlation in globular cluster systems has been used as an argument against self-enrichment models of…
We present predictions of the evolution of the light elements, Li, Be, and B, in the early epochs of the Galactic halo, using a model of supernova-induced chemical evolution based on contributions from supernovae (SNe) and cosmic rays…
We take advantage of the largest high-resolution simulation of cosmic structure growth ever carried out -- the Millennium Simulation of the concordance LambdaCDM cosmogony -- to study how the star formation histories, ages and metallicities…
We present recent progress on quantitative estimation of stellar ages using ind icators such as theoretical evolutionary tracks, rotation, rotation-driven chrom ospheric and coronal activity, and lithium depletion. Our focus is on roughly…
We use detailed modeling of stellar populations of nearby galaxies to calculate population parameters. Our sample of galaxies includes most galaxies of the Local Group and several more distant giant galaxies. Available data are sufficient…
The halo and disc globular cluster population can be used as a tracer of the primordial epochs of the Milky Way formation. In this work, literature data of globular clusters ages, chemical abundances, and structural parameters are studied,…