Related papers: Color Bimodality in M87 Globular Clusters
Relative ages for the globular cluster (GC) subpopulations in the Virgo giant elliptical galaxy M87 (NGC 4486) have been determined from Stroemgren photometry obtained with WFPC2 on board HST. Using a variety of population synthesis models,…
We present the correlations between the spectroscopic metallicities and ninety-three different intrinsic colors of M31 globular clusters, including seventy-eight BATC colors and fifteen SDSS and near infrared ugrizK colors. The BATC colors…
We have observed three fields of the Coma cluster of galaxies with a narrow band (modified Stromgren) filter system. Observed galaxies include 31 in the vicinity of NGC 4889, 48 near NGC 4874, and 60 near NGC 4839 complete to M_5500=-18 in…
As part of the SLUGGS survey, we stack 1137 Keck DEIMOS spectra of globular clusters from 10 galaxies to study their stellar populations in detail. The stacked spectra have median signal to noise ratios of $\sim 90$ \AA$^{-1}$. Besides the…
We explore the relative role of small-scale fragmentation and global collapse in low-metallicity clouds, pointing out that in such clouds the cooling time may be longer than the dynamical time, allowing the cloud to collapse globally before…
Globular clusters show abundance variations for light elements that are not yet well understood. The preferred explanation involves a self-enrichment scenario, with two subsequent generations of stars. Observations of main sequence stars…
The observed mass-to-light ($M/L$) ratios of a large sample of GCs in M31 show an inverse trend with metallicity compared to what is expected from Simple Stellar Population (SSP) models with an invariant canonical stellar IMF, in the sense…
We examine the globular cluster systems (GCS) of a sample of 34 S0 galaxies from a WFPC2 snapshot survey in the V and I-bands. Of these 34 galaxies, 29 have measurable globular cluster systems. The mean color of the GCSs of individual…
We derive structural parameters for ~2000 globular clusters in the giant Virgo elliptical M87 using extremely deep Hubble Space Telescope images in F606W (V) and F814W (I) taken with the ACS/WFC. The cluster scale sizes (half-light radii…
We carry out a joint spatial-kinematical-metallicity analysis of globular clusters (GCs) around the Andromeda Galaxy (M31), using a homogeneous, high-quality spectroscopic dataset. In particular, we remove the contaminating young clusters…
We present new Hubble Space Telescope imaging of the outer regions of M87 in order to study its globular cluster (GC) population out to large galactocentric distances. We discuss particularly the relationship between GC effective radii…
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…
We have imaged with HST's WFC3/UVIS the central 2.7$\times$2.7 arcmin$^2$ region of the giant elliptical galaxy M 87, using the ultraviolet filter F275W. In combination with archival ACS/WFC data taken through the F606W and F814W filters,…
Updated data of the 153 Galactic globular clusters are used to readdress fundamental parameters of the Milky Way. We build a reduced sample, decontaminated of the clusters younger than 10Gyr, those with retrograde orbits and/or evidence of…
Although the colour distribution of globular clusters in massive galaxies is well known to be bimodal, the spectroscopic metallicity distribution has been measured in only a few galaxies. After redefining the calcium triplet…
Using photometric data from the 2MASS second incremental release point source catalog we constructed Ks vs. (J-Ks) color-magnitude diagrams (CMDs) of Galactic globular clusters (GGCs) for which the JKs photometric data have been made…
Metal-poor globular clusters (GCs) show intriguing Al-Mg and Si-Al correlations, which are important clues to decipher the multiple population phenomenon. NGC 5053 is one of the most metal-poor GCs, and has been suggested to be associated…
We have developed an homogeneous evolutionary scenario for H- and He-burning low-mass stars by computing updated stellar models for a wide metallicity and age range (0.0002$\le Z \le$0.004 and 9$\le t(Gyr) \le$15, respectively) suitable to…
We have analyzed archival HST/ACS images in Sloan g and z of the globular cluster (GC) systems of 53 ellipticals in the Virgo Cluster, spanning massive galaxies to dEs. Among the new results are: (1) In the gEs M87 and NGC 4649, there is a…
Globular cluster (GC) systems around galaxies of a vast mass range show remarkably simple scaling relations. The combined mass of all GCs is a constant fraction of the total galaxy mass and the mean metallicity and metallicity dispersion of…