相关论文: MIUSCAT: extended MILES spectral coverage. II. Con…
A galaxy's stellar mass-to-light ratio ($M_\star/L$) is a useful tool for converting luminosity to stellar mass ($M_\star$). However, the practical utility of $M_\star/L$ inferred from stellar population synthesis (SPS) models is limited by…
Stellar clusters are thought to be the simplest stellar systems and the closest observational counterparts to theoretical models for single stellar populations. Progress in our understanding of the atmospheres and evolution of massive stars…
The GALEX (Galaxy Evolution Explorer) Nearby Galaxies Survey is providing deep far-UV and near-UV imaging for a representative sample of galaxies in the local universe. We present early results for M51 and M101, from GALEX UV imaging and…
Using a sample of nearly 20,000 massive early-type galaxies selected from the Sloan Digital Sky Survey, we study the color-magnitude relation for the most luminous (L > 2.2 L^{*}) field galaxies in the redshift range 0.1<z<0.4 in several…
This review summarises the main properties of Young Massive Clusters (YMCs), including their population properties, particularly focusing on extragalactic cluster samples. We discuss potential biases and caveats that can affect the…
Mayall II = G1 is one of the most luminous globular clusters (GCs) in M31. Here, we determine its age and mass by comparing multicolor photometry with theoretical stellar population synthesis models. Based on far- and near-ultraviolet GALEX…
Wide-area imaging surveys are one of the key ways of advancing our understanding of cosmology, galaxy formation physics, and the large-scale structure of the Universe in the coming years. These surveys typically require calculating…
We constrain the stellar population properties of a sample of 52 massive galaxies, with stellar mass log Ms>10.5, over the redshift range 0.5<z<2 by use of observer-frame optical and near-infrared slitless spectra from HST's ACS and WFC3…
Integrated spectroscopy is the method of choice for deriving the ages of unresolved stellar systems. However, hot stellar evolutionary stages, such as hot horizontal branch stars and blue straggler stars (BSSs), can affect the integrated…
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 test the performance of our analysis technique for integrated-light spectra by applying it to seven well-studied Galactic GCs that span a wide range of metallicities. Integrated-light spectra were obtained by scanning the slit of the…
A study of aperture size effects on star cluster photometry in crowded fields is presented. Tests were performed on a sample of 285 star cluster candidates in the South-West field of the M31 galaxy disk, measured in the Local Group Galaxy…
The details of bulge formation via collapse, mergers, secular processes or their interplay remain unresolved. To start answering this question and quantify the importance of distinct mechanisms, we mapped a sample of three galactic bulges…
In a 1$^{\rm st}$ step I present results from our new set of evolutionary synthesis models for Simple (= single burst) Stellar Populations ({\bf SSP}s) of various metallicities, and in a 2$^{\rm nd}$ step I combine these results with the…
For many years broadband colours have been used to obtain insight into the contents of galaxies, in particular to estimate stellar and dust content. Broadband colours are easy to obtain for large samples of objects, making them ideal for…
In this paper, we present photometry of 53 globular clusters (GCs) in the M31 outer halo, including the {\sl GALEX} FUV and NUV, SDSS $ugriz$, 15 intermediate-band filters of BATC, and 2MASS $JHK_{\rm s}$ bands. By comparing the multicolour…
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 examine the outer structure of 12 Galactic globular clusters using star-count analyses. Deep, two-color, photographic photometry is used to select and count stars with colors and magnitudes consistent with cluster-specific,…
We present a thorough quantitative analysis of the evolution of the colour-magnitude relation for early-type galaxies in 17 distant clusters with redshifts 0.31 < z < 1.27 using the Kodama & Arimoto (1997) evolutionary model for elliptical…
(Abridged) We analyze photometry and spectroscopy of a sample of 63 clusters at 0.3<z<0.9 drawn from the Las Campanas Distant Cluster Survey to empirically constrain models of cluster galaxy evolution. Specifically, by combining data on our…