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The comparative chemical evolution of an isolated dwarf galaxy: a vlt and keck spectroscopic survey of wlm

Citation

Leaman, R and Venn, KA and Brooks, AM and Battaglia, G and Cole, AA and Ibata, RA and Irwin, MJ and McConnachie, AW and Mendel, JT and Starkenburg, E and Tolstoy, E, The comparative chemical evolution of an isolated dwarf galaxy: a vlt and keck spectroscopic survey of wlm, Astrophysical Journal, 767, (2) Article 131. ISSN 0004-637X (2013) [Refereed Article]


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Copyright 2013 The American Astronomical Society

DOI: doi:10.1088/0004-637X/767/2/131

Abstract

Building on our previous spectroscopic and photometric analysis of the isolated Local Group dwarf irregular (dIrr) galaxy WLM, we present a comparison of the metallicities of its red giant branch stars with respect to the well-studied Local Group dwarf spheroidal galaxies (dSphs) and Magellanic Clouds. We calculate a mean metallicity of [Fe/H] =–1.28 ± 0.02 and an intrinsic spread in metallicity of σ = 0.38 ± 0.04 dex, similar to the mean and spread observed in the massive dSph Fornax and the Small Magellanic Cloud. Thus, despite WLM's isolated environment, its global metallicity still follows expectations for mass and its global chemical evolution is similar to other nearby luminous dwarf galaxies (gas-rich or gas-poor). The data also show a radial gradient in [Fe/H] of d[Fe/H]/drc = –0.04 ± 0.04 dex rc-1, which is flatter than that seen in the unbiased and spatially extended surveys of dSphs. Comparison of the spatial distribution of [Fe/H] in WLM, the Magellanic Clouds, and a sample of Local Group dSphs shows an apparent dichotomy in the sense that the dIrrs have statistically flatter radial [Fe/H] gradients than the low angular momentum dSphs. The correlation between angular momentum and radial metallicity gradient is further supported when considering the Local Group dEs. This chemodynamic relationship offers a new and useful constraint for environment-driven dwarf galaxy evolution models in the Local Group.

Item Details

Item Type:Refereed Article
Keywords:galaxies: abundances – galaxies: dwarf – galaxies: evolution – galaxies: individual (WLM) – Local Group
Research Division:Physical Sciences
Research Group:Astronomical and Space Sciences
Research Field:Cosmology and Extragalactic Astronomy
Objective Division:Expanding Knowledge
Objective Group:Expanding Knowledge
Objective Field:Expanding Knowledge in the Physical Sciences
Author:Cole, AA (Associate Professor Andrew Cole)
ID Code:86251
Year Published:2013
Web of Science® Times Cited:34
Deposited By:Mathematics and Physics
Deposited On:2013-08-30
Last Modified:2017-11-30
Downloads:15 View Download Statistics

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