Related papers: Intermediate-age Globular Clusters in Four Galaxy …
We present spectroscopic ages, metallicities, and [alpha/Fe] ratios for 70 globular clusters in M31 that were derived from Lick line-index measurements. In addition to a population of old (>10 Gyr) globular clusters with a wide range of…
We present Hubble Space Telescope ACS deep photometry of the intermediate-age globular cluster NGC 1783 in the Large Magellanic Cloud. By using this photometric dataset, we have determined the degree of ellipticity of the cluster…
We study the properties of the globular cluster system of the ``old'' merger NGC 5018. We detect a relatively poor globular cluster system, that can be divided into at least two populations based on colors: a small population of blue…
Old Globular Clusters (GCs) in the Milky Way have ages of about 13 Gyr, placing their formation time in the reionization epoch. We propose a novel scenario for the formation of these systems based on the merger of two or more atomic cooling…
Based on a new large, homogeneous photometric database of 35 Galactic globular clusters (GGCs), a set of distance and reddening independent relative age indicators has been measured. The observed D(V-I)_2.5 and D(V)(HB-TO) vs. metallicity…
We revisit the determination of the age of the Universe from galactic globular clusters, extending previous analyses by explicitly accounting for the presence of multiple stellar populations within each cluster. Using high--quality…
The color distributions of globular clusters (GCs) in individual early-type galaxies show great diversity in their morphology. Based on the conventional "linear" relationship between the colors and metallicities of GCs, the GC metallicity…
This paper presents results from wide-field imaging of the globular cluster (GC) systems of five intermediate-luminosity (M_V ~-21 to -22) early-type galaxies. The aim is to accurately quantify the global properties of the GC systems by…
We present a study of globular clusters (GCs) in 17 relatively nearby early-type galaxies, based on deep HST/WFPC2 F555W and F814W images. We compare color distributions, cluster sizes and luminosity functions with those of GCs in the Milky…
In previous papers of the series we used a combination of optical and near-infrared colours to derive constraints on the relative age structure in globular cluster systems. Here, we present the details, strength and limitations of our…
Imaging spectroscopy using the new Palomar Integral Field Spectrograph is presented for the Pa-alpha line in four ultraluminous infrared galaxies. In most cases, we are able to establish the geometry of the merger, and thus estimate the…
We present Gemini South GMOS g,i photometry of 14 intermediate-age Large Magellanic Cloud (LMC) star clusters, namely: NGC 2155, 2161, 2162, 2173, 2203, 2209, 2213, 2231, 2249, Hodge 6, SL 244, 505, 674, and 769, as part of a continuing…
The small group of Galactic Globular Clusters (GGC) (Pal 12, Terzan 7, Ruprecht 106, Arp 2) recently discovered to be significantly younger (by ~3-4 Gyr) than the average cluster population of the Galaxy are shown to lie near planes passing…
We derive ages, metallicities and [alpha/Fe] ratios from the integrated spectra of 23 globular clusters in M31, by employing multivariate fits to two stellar population models. In parallel we analyze spectra of 21 Galactic globular clusters…
Recent observations of globular clusters (GCs) in intermediate-age (2-4 Gyr old), early-type merger remnants have provided the hitherto `missing link' between young merger remnants and `normal' elliptical galaxies in the form of a GC…
We present deep, photometrically calibrated BVRJHK images of the nearby interacting galaxy pair NGC 4038/39 (``The Antennae''). Color maps of the images are derived, and those using the B, V, and K-bands are analyzed with techniques…
We present measurements of ages, metallicities, and [alpha/Fe] ratios for 16 globular clusters (GC) in NGC 147, NGC 185, and NGC 205 and of the central regions of the diffuse galaxy light in NGC 185, and NGC 205. Our results are based on…
This is the second paper in our series about the search for multiple populations in Magellanic Cloud star clusters using the Hubble Space Telescope. Here we report the detection of multiple stellar populations in the colour-magnitude…
We report on $BVI$ CCD photometry to $V=22.0$ for 3 fields centered on the region of the Galactic star clusters Ruprecht~4, Ruprecht~7 and Pismis~15 and on 3 displaced control fields. Ruprecht~4 and Pismis~15 have never been studied before,…
Various methods for age dating globular clusters in ellipticals are presented. We first present spectroscopy of individual globular clusters (feasible with the advent of the 10m-class telescopes), and the measurement of Balmer line indices.…