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Photometric metallicity map of the Large Magellanic Cloud

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journal contribution
posted on 2023-05-18, 18:06 authored by Choudhury, S, Subramaniam, A, Andrew ColeAndrew Cole
We have estimated a metallicity map of the Large Magellanic Cloud (LMC) using the Magellanic Cloud Photometric Survey (MCPS) and Optical Gravitational Lensing Experiment (OGLE III) photometric data. This is a first of its kind map of metallicity up to a radius of 4°–5°, derived using photometric data and calibrated using spectroscopic data of Red Giant Branch (RGB) stars. We identify the RGB in the V, (VI) colour–magnitude diagrams of small subregions of varying sizes in both data sets. We use the slope of the RGB as an indicator of the average metallicity of a subregion, and calibrate the RGB slope to metallicity using spectroscopic data for field and cluster red giants in selected subregions. The average metallicity of the LMC is found to be [Fe/H] = −0.37 dex (σ[Fe/H] = 0.12) from MCPS data, and [Fe/H] = −0.39 dex (σ[Fe/H] = 0.10) from OGLE III data. The bar is found to be the most metal-rich region of the LMC. Both the data sets suggest a shallow radial metallicity gradient up to a radius of 4 kpc (−0.049 ± 0.002 dex kpc−1 to −0.066 ± 0.006 dex kpc−1). Subregions in which the mean metallicity differs from the surrounding areas do not appear to correlate with previously known features; spectroscopic studies are required in order to assess their physical significance


Department of Industry, Science, Energy and Resources


Publication title

Monthly Notices of the Royal Astronomical Society








School of Natural Sciences


Blackwell Publishing Ltd

Place of publication

9600 Garsington Rd, Oxford, England, Oxon, Ox4 2Dg

Rights statement

Copyright 2015 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.

Repository Status

  • Open

Socio-economic Objectives

Expanding knowledge in the physical sciences