CCD SDSS gr Photometry of Poorly Studied Star Clusters in the Large Magellanic Cloud

Andrés E Piatti

doi:10.1155/2014/398182

Abstract

We present for the first time CCD SDSS gr photometry, obtained at the Gemini South telescope with the GMOS attached, of stars in the field of the poorly studied star clusters NGC1768, HS 85, SL 676, NGC2107, NGC2190, and SL 866, which are distributed in the main body of the Large Magellanic Cloud. We applied a subtraction procedure to statistically clean the cluster CMDs from field star contamination. In order to disentangle cluster features from those belonging to their surrounding fields, we applied a subtraction procedure which makes use of variable cells to reproduce the field star color-magnitude diagrams (CMDs) as closely as possible. We then traced their stellar density radial profiles from star counts performed over the cleaned field stars dataset and derived their radii. Using the cleaned cluster CMDs, we estimated ages and metallicities from matching theoretical isochrones computed for the SDSS system. The studied star clusters have ages from 0.1 up to 2.0 Gyr and are of slightly metal-poor metal content ([Fe/H]≈−0.4 dex).

Highlights

The Large Magellanic Cloud (LMC) harbors more than two thousand catalogued ordinary star clusters [1]
We present for the first time CCD SDSS gr photometry, obtained at the Gemini South telescope with the Gemini multiobject spectrograph (GMOS) attached, of stars in the field of the poorly studied star clusters NGC1768, HS 85, SL 676, NGC2107, NGC2190, and SL 866, which are distributed in the main body of the Large Magellanic Cloud
Using the cleaned cluster color-magnitude diagrams (CMDs), we estimated ages and metallicities from matching theoretical isochrones computed for the SDSS system

Summary

Introduction

The Large Magellanic Cloud (LMC) harbors more than two thousand catalogued ordinary star clusters [1]. They are prime indicators of the chemical evolution and the star formation history of the galaxy, only a very small percentage has been well studied [2, 3]. In this sense, detailed investigations of even a handful of clusters represent a significant improvement of our knowledge of the chemical enrichment history of this galaxy.

Data Handling

Analysis of the Color-Magnitude Diagrams

Cluster Fundamental Parameters

Findings

Analysis and Discussion

Summary