Related papers: HR-pyPopStar: high wavelength-resolution stellar p…
We present model spectra of stellar populations with variable chemical composition. We derived the [alpha/Fe] abundance ratio of the stars of the most important libraries (ELODIE, CFLIB and MILES) using full spectrum fitting and we…
In this review, I will discuss a few problems which point to the need for improved stellar evolution models of halo stars. Current stellar evolution models do not match the observed $^7$Li abundance patterns, suggesting that the input…
Theoretical stellar evolution models are constructed and tailored to the best known, observationally derived characteristics of metal-poor ([Fe/H]$\sim-2.3$) stars representing a range of evolutionary phases: subgiant HD140283, globular…
Observations show that nearly all star clusters and stellar populations contain blue straggler stars (BSs). BSs in a cluster can significantly enhance the integrated spectrum of the host population, preferentially at short wavelengths, and…
We would like to find a way to improve the determination of galaxy star formation history from integrated light spectroscopy. To this end, several classes of chemically peculiar (CP) stars arise during the course of normal evolution in…
We present new evolutionary synthesis models for Single Stellar Populations covering a wide range in age and metallicity. The most important difference with existing models is the use of NLTE atmosphere models for the hot stars (O, B, WR,…
We present a detailed investigation of the young stellar populations(YSP) in the radio-loud ultra luminous infrared galaxy (ULIRG) PKS1345+12, based on high resolution HST imaging and long slit spectra taken with the WHT. While the images…
We present stellar atmosphere and evolution models of main sequence stars in two stellar populations of the Galactic globular cluster NGC 6752. These populations represent the two extremes of light-element abundance variations in the…
We summarise recent developments on synthesis models for massive star populations with a particular emphasis on Wolf-Rayet (WR) stars. Quantitative analysis of the stellar content of WR galaxies are reviewed. Comparing observations of WR…
We present the first calculations to follow the evolution of all stable nuclei and their radioactive progenitors in stellar models computed from the onset of central hydrogen burning through explosion as Type II supernovae. Calculations are…
We present a novel statistical algorithm, Stellar Ages, which currently infers the age, metallicity, and extinction posterior distributions of stellar populations from their magnitudes. While this paper focuses on these parameters, the…
Surface temperature distribution of horizontal-branch (HB) stars is very sensitive to age in old stellar systems, which makes it an attractive age indicator. In this paper, we present the recent revision of our model calculations for the HB…
In this contribution I present my current work in a new generation of evolutionary synthesis models that compute the multiwavelength energy distribution (from gamma-rays to radio) as well as the associated dispersion for young stellar…
We describe a technique for deriving effective temperatures, surface gravities, rotation velocities, and radial velocities from high resolution near-IR spectra. The technique matches the observed near-IR spectra to spectra synthesized from…
We present a new set of horizontal-branch (HB) models computed with the MESA stellar evolution code. The models adopt $\alpha$-enhanced \cite{ags09} metals mixtures and include the gravitational settling of He. They are used in our HB…
Taking advantage of recent important advances in the calculation of high-resolution spectral grids of stellar atmospheres at short wavelengths, and their implementation for population synthesis models, we briefly review here some special…
The efficient use of near-IR data in studies of external stellar populations depends on our ability to recognize the nature of the predominant sources of light, and to interprete these findings in terms of age and metallicity. Here we focus…
Large-scale spectroscopic surveys have collectively observed millions of stars across the Milky Way, but each derives stellar labels using independent pipelines with distinct modelling assumptions, introducing systematic offsets that…
We present differential stellar population models, which allow improved determinations of the ages, iron and alpha-element abundances of old stellar populations from spectral fitting. These new models are calibrated at solar abundances…
This review deals with stellar population models computed by means of the evolutionary synthesis technique that was pioneered by Beatrice Tinsley roughly three decades ago. The focus is on the simplest models, the so called Simple Stellar…