CCD photometry of Large Magellanic Cloud clusters. II - The intermediate-age cluster H4

We have obtained Washington CCD photometry with the CTIO 4m and 1.5m for ˜50 intermediate-to-old age star clusters in the Clouds. The data extend to near or below the main sequence and provide excellent photometry for the giants, from which precise (internal errors <0.1 dex) mean cluster abundances can be determined. We present data for several of the clusters and discuss the results. Intermediate resolution spectra have also been obtained for some 16 clusters with the CTIO 4m ARGUS multiple-object fibre-fed spectrograph. Finally, we have also obtained high dispersion (R˜20,000) échelle spectra for several of the brighter giants in a small sample of Large Magellanic Cloud (LMC) clusters. Detailed elemental abundances derived from these spectra will be presented. These data will help refine our knowledge of the age-metallicity relation in the Clouds.

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CCD photometry of Large Magellanic Cloud clusters. IV - The metal-rich, remote southern cluster LW 79

The Astrophysical Journal ◽

10.1086/165581 ◽

1987 ◽

Vol 320 ◽

pp. 626 ◽

Cited By ~ 7

Author(s):

Mario Mateo ◽

Paul Hodge

Keyword(s):

Large Magellanic Cloud ◽

Magellanic Cloud ◽

Ccd Photometry ◽

Cloud Clusters

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Star clusters in the Magellanic Clouds

Symposium - International Astronomical Union ◽

10.1017/s0074180900200259 ◽

1991 ◽

Vol 148 ◽

pp. 161-164 ◽

Cited By ~ 1

Author(s):

S. van den Bergh

Keyword(s):

Cluster Formation ◽

Star Clusters ◽

Large Magellanic Cloud ◽

Magellanic Cloud ◽

Magellanic Clouds ◽

Open Clusters ◽

Small Magellanic Cloud ◽

Cloud Clusters ◽

The Galaxy

Star clusters in the Magellanic Clouds (MCs) differ from those in the Galaxy in a number of respects: (1) the Clouds contain a class of populous open clusters that has no Galactic counterpart; (2) Cloud clusters have systematically larger radii rh than those in the Galaxy; (3) clusters of all ages in the Clouds are, on average, more flattened than those in the Galaxy. In the Large Magellanic Cloud (LMC) there appear to have been two distinct epochs of cluster formation. LMC globulars have ages of 12-15 Gyr, whereas most populous open clusters have ages <5 Gyr. No such dichotomy is observed for clusters in the Small Magellanic Cloud (SMC) The fact that the SMC exhibits no enhanced cluster formation at times of bursts of cluster formation in the LMC, militates against encounters between the Clouds as a cause for enhanced rates of star and cluster formation.

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The Abundance of the LMC Globular Cluster NGC 2213

Symposium - International Astronomical Union ◽

10.1017/s0074180900043163 ◽

1988 ◽

Vol 126 ◽

pp. 579-580

Author(s):

Doug Geisler

Keyword(s):

Globular Cluster ◽

Main Sequence ◽

High Accuracy ◽

Magellanic Cloud ◽

New Technique ◽

Distance Modulus ◽

Ccd Photometry ◽

Cloud Clusters ◽

A New Technique ◽

Using Data

A new technique for determining accurate abundances in distant giants - Washington CCD photometry - has been applied to the intermediate-age LMC globular cluster NGC 2213. An abundance of −0.40 ± 0.15 was found from the analysis of 42 giants with V < 20, using data obtained with the 1.5 m telescope. Combined with published main-sequence photometry, the derived abundance indicates a true LMC distance modulus of 18.2 ± 0.2. A likely CN strong giant near the tip of the giant branch is identified. Abundances are also derived for a sample of 27 field giants. Results indicate that one could determine both the age and abundance of Magellanic Cloud clusters with high accuracy from Washington photometry using the 4 m in less than one hour of observing time per cluster.

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