相关论文: Stellar Populations in Normal Galaxies

In order to build more realistic single stellar population (SSP) models with variable alpha-enhancement, we have recently determined [Mg/Fe] in a uniform scale with a precision of about 0.1 dex for 752 stars in the MILES empirical library.…

Recent observations supported by theoretical models have lead to the view that giant and supergiant stars are over abundant, and/or a high metallicity component may be present, in the stellar populations at the centres of active galaxies.…

The growth of sky surveys and the large amount of stellar spectra in the current databases, has generated the necessity of developing new methods to estimate atmospheric parameters, a fundamental task on stellar research. In this work we…

Comparison with artificial galaxy models is essential for translating the incomplete and low signal-to-noise data we can obtain on astrophysical stellar populations to physical interpretations which describe their composition, physical…

To study the stellar population of local infrared galaxies, which contain star-forming galaxies, composite galaxies, LINERs, and Seyfert 2s. We also want to find whether infrared luminosity and spectral class have any effects on their…

Theoretical stellar spectra rely on model stellar atmospheres computed based on our understanding of the physical laws at play in the stellar interiors. These models, coupled with atomic and molecular line databases, are used to generate…

We present FEROS--Lick/SDSS, an empirical database of Lick/SDSS spectral indices of FGK stars to be used in population synthesis projects for discriminating different stellar populations within the integrated light of galaxies and globular…

We are developing a brand new stellar population models with flexible chemistry (isochrones plus stellar colors and spectra) in order to set a new standard of completeness and excellence. Here we present preliminary results to assess the…

We present an empirical infrared spectral library of medium resolution (R~2000-3000) H (1.6 micron) and K (2.2 micron) band spectra of 218 red stars, spanning a range of [Fe/H] from ~-2.2 to ~+0.3. The sample includes Galactic disk stars,…

Combining population synthesis models with simple Montecarlo simulations of stochastic effects in the number of stars occupying sparsely populated stellar evolutionary phases in the HRD, I show that the scatter observed in the photometric…

We present UV-extended E-MILES stellar population synthesis models covering the spectral range 1680-50000A at moderately high resolution. We employ the NGSL space-based stellar library to compute spectra of single-age, single-metallicity…

We present techniques for the estimation of stellar atmospheric parameters (Teff,logg,[Fe/H]) for stars from the SDSS/SEGUE survey. The atmospheric parameters are derived from the observed medium-resolution (R=2000) stellar spectra using…

We want to develop spectral diagnostics of stellar populations in the near-infrared (NIR), for unresolved stellar populations. We created a semi-empirical population model and we compare the model output with the observed spectra of a…

It is now possible to measure detailed spectral indices for stellar populations in spiral disks. We propose to interpret these data using evolutionary synthesis models computed from the Star Formation Histories obtained from chemical…

A catalogue of superclusters of galaxies is used to investigate the influence of the supercluster environment on galaxy populations, considering galaxies brighter than M$_r<$-21+5$\log$ h. Empirical spectral synthesis techniques are applied…

Planetary nebulae represent a potential late stage of stellar evolution, however the central stars (CSPNe) are relatively faint and therefore pertinent information is merely available for <20% of the Galactic sample. Consequently, the…

We built modelled spectra of stellar population at high resolution and with variable alpha-elements enhancements. Analysing spectra of Galactic globular clusters we show that it is possible to derive reliably and efficiently [Mg/Fe] using…

(Abridged) We introduce a novel technique to construct spatially resolved maps of stellar mass surface density in galaxies based on optical and near IR imaging. We use optical/NIR colour(s) to infer effective stellar mass-to-light ratios…

Libraries of stellar spectra, such as ELODIE (Prugniel & Soubiran 2001), CFLIB (Valdes et al. 2004), or MILES (S\'anchez-Bl\'azquez et al. 2006), are used for a variety of applications, and especially in modelling stellar populations (e. g.…

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…