相关论文: Stroemgren metallicity calibration: the m1, b-y re…

We present two absolute magnitude calibrations, $M_{J}$ and $M_{K_s}$, for red giants with the colour magnitude diagrams of five Galactic clusters with different metallicities i.e. M92, M13, M71, M67, and NGC 6791. The combination of the…

We present a theoretical calibration of the RR Lyrae period-luminosity-color and period-color-color relations in the multiband uvby Stroemgren photometric system. Our theoretical work is based on calculations of synthetic horizontal…

We present a technique that applies spectral synthesis to medium resolution spectroscopy (MRS, R ~ 6000) in the red (6300 A < lambda < 9100 A) to measure [Fe/H] and [alpha/Fe] of individual red giant stars over a wide metallicity range. We…

The individual reddenings for B stars in two fields in the Small Magellanic Cloud (SMC) and two fields in the Large Magellanic Cloud (LMC) are determined by means of Stroemgren uvby CCD photometry. In both LMC fields we find a foreground…

A non-LTE analysis of K I resonance lines at 7664.91 and 7698.97 A was carried out for 15 red giants belonging to three globular clusters of different metallicity (M 4, M 13, and M 15) along with two reference early-K giants (rho Boo and…

The observed characteristics of globular cluster (GC) systems, such as metallicity distributions, are commonly used to place constraints on galaxy formation models. However, obtaining reliable metallicity values is particularly difficult…

In this paper we present catalogs of photometric and spectroscopic data for M81 globular clusters (GCs). The catalogs include B- and V- photometric and reddening data of 95 GCs, and spectroscopic metallicities of 40 GCs in M81. Using these…

Taking advantage of the near-infrared calcium triplet lines, we determine metallicities for a sample of more than 3,500 red giant stars in the field of the Small Magellanic Cloud (SMC). We find a median metallicity of [Fe/H]=-1.05$\pm$0.01…

We present a direct determination of the stellar metallicity in the close pair galaxy NGC~4038 (D = 20 Mpc) based on the quantitative analysis of moderate resolution KMOS/VLT spectra of three super star clusters (SSCs). The method adopted…

The mean metallicity of the Milky Way thin disc in the solar neighbourhood is still a matter of debate, and has recently been subject to upward revision (Haywood, 2001). Our star sample was drawn from a set of solar neighbourhood dwarfs…

We discuss a variety of photometric indices assembled from the uvby Stromgren system. Our aim is to examine the pros and cons of the various indices to find the most suitable one(s) to study the properties of multiple populations in…

The surface brightness - color relationship (SBCR) is a poweful tool for determining the angular diameter of stars from photometry. It was for instance used to derive the distance of eclipsing binaries in the Large Magellanic Cloud (LMC),…

Red clump (RC) stars are widely used as an excellent standard candle. To make them even better, it is important to know the dependence of their absolute magnitudes on age and metallicity. We observed star clusters in the Large Magellanic…

We present an empirical calibration of the Mixing-Length free parameter ${\alpha}$ based on a homogeneous Infrared database of 28 Galactic globular clusters spanning a wide metallicity range (-2.15$<$[Fe/H]$<$-0.2). Empirical estimates of…

We present evolutionary models for low mass stars from 0.075 to 1 $\msol$ for solar-type metallicities [M/H]= 0 and -0.5. The calculations include the most recent interior physics and the latest generation of non-grey atmosphere models. We…

We have obtained spectra at the Ca II triplet of individual red giants in seven SMC star clusters whose ages range from ~4 to 12 Gyr. The spectra have been used to determine mean abundances for six of the star clusters to a typical…

The pulsational method to estimate the absolute magnitudes of RR Lyrae stars is updated with new data on field-star metallicities by Layden, a new calibration of the (B-V)_0-temperature correlation from recent atmospheric models by Bell and…

We have employed feedforward neural networks trained on synthetic spectra in the range 3800 to 5600 AA with resolutions of 2-3 AA to determine metallicities from spectra of about 1000 main-sequence turn-off, subgiant and red giant stars in…

We present adaptive-optics assisted near-infrared high-spectral resolution observations of late-type giants in the nuclear star cluster of the Milky Way. The metallicity and elemental abundance measurements of these stars offer us an…

We present mean horizontal branch absolute magnitudes and iron abundances for a sample of 39 globular clusters. These quantities were calculated in an unprecedented homogeneous fashion based on Fourier decomposition of ligt curves of RR…