相关论文: Broad-band colour evolution of star clusters

We investigate the origin of color gradients in cluster early-type galaxies to probe whether pure age or pure metallicity gradients can explain the observed data in local and distant (z approx 0.4) samples. We measure the surface brightness…

Using the Subaru very deep K'-band imaging and HST WFPC2/NICMOS archival data of the Hubble Deep Field North, we investigate the evolution of the stellar mass, color, morphology of galaxies to z ~ 3. We mainly examine the rest-frame U-V…

We have measured an extensive set of UBVRIJHK colors for M31 globular clusters [Barmby et al. 2000]. We compare the predicted simple stellar population colors of three population synthesis models to the intrinsic colors of Galactic and M31…

Several population synthesis models now predict integrated colors of simple stellar populations in the mid-infrared bands. To date, the models have not been extensively tested in this wavelength range. In a comparison of the predictions of…

We present the results of our analysis of the photometric data of globular clusters in the elliptical galaxy NGC 5128 (Cen A). We show that the integrated colour U-B can be an effective metallicity indicator for simple stellar populations.…

We have assembled a UV-flux selected sample of 82 early-type galaxies and collected additional information at other wavelengths. These data confirm a large spread of the UV-V color in the range 2 to 5. The spread in UV-V is accompanied by a…

We present a detailed U-V CMR analysis for 3 local (z<0.06) Abell (A85, A496, A754) galaxy clusters, with 637 total spectroscopic members down to 0.1L^star. We find that these clusters have similar CMRs with a mean color of U-V=1.4 at…

New Johnson-Cousins UBVRI photometry of giants in globular clusters is combined with JHK photometry on the CIT system to produce color sequences for giants from the globular clusters M3, M5, M13, and M92. UBVRI data are also presented for…

(ABRIDGED) We assess the systematic uncertainties in (young) cluster age, mass, and - to a lesser extent - extinction and metallicity determinations, based on broad-band imaging observations with the Hubble Space Telescope. Our aim here is…

The integrated colors of distant galaxies provide a means for interpreting the properties of their stellar content. Here, we use rest-frame UV-to-optical colors to constrain the spectral-energy distributions and stellar populations of…

Using Monte Carlo simulations of globular clusters we developed a method separating metallicity effects from age effects on observed integrated ugriz colors. We demonstrate that these colors do not evolve with time significantly after an…

We present B, V, R, and H alpha photometry of 8 clusters in the Small Magellanic Cloud, 5 in the Large Magellanic Cloud, and 3 Galactic clusters, and use 2 color diagrams (2-CDs) to identify candidate Be star populations in these clusters.…

A high number of embedded clusters is found in the Galaxy. Depending on the formation scenario, most of them can evolve to unbounded groups that are dissolved within a few tens of Myr. A systematic study of young stellar clusters showing…

Using a widely used stellar population synthesis model, we study the ability of using pairs of AB system colours to break the well-known stellar age--metallicity degeneracy and give constraints on the two stellar-population parameters (age…

Star formation plays a central role in the evolution of galaxies and of the Universe as a whole. Studies of star-forming regions in the local universe have shown that star formation typically occurs in a clustered fashion. Building a…

We have developed an analytical method to investigate the stellar populations in a galaxy using the broad-band colours. The method enables us to determine the relative contribution, spatial distribution and age for different stellar…

(ABBREVIATED:) The large majority of extragalactic star cluster studies done to date have essentially used two or three-passband aperture photometry, combined with theoretical stellar population synthesis models, to obtain age, mass and…

We present UBVI photometry for the old open cluster Collinder 261. From comparison of the observed colour-magnitude diagrams with simulations based on stellar evolutionary models we derive in a self consistent way reddening, distance, and…

We use a combination of deep optical (gri) and near-infrared (H) photometry to study the radially-resolved colours of a broad sample of 300 Virgo cluster galaxies. For most galaxy types, we find that the median g-H colour gradient is either…

Evolutionary synthesis models for star clusters of various metallicities including gaseous emission during the lifetime of the ionising stars are used to model star cluster systems comprising two populations: an old metal-poor globular…