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arXiv · 0807.3545

Stellar population gradients in early-type cluster galaxies with VIMOS IFU

T. D. Rawle·Russell J. Smith·J. R. Lucey·A. M. Swinbank
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Abstract

We present results from a pilot study of radial stellar population trends in early-type galaxies using the VLT VIMOS integral field unit (IFU). We observe twelve galaxies in the cluster Abell 3389 (z~0.027). For each galaxy, we measure 22 line-strength indices in multiple radial bins out to at least the effective radius. We derive stellar population parameters using a grid inversion technique, and calculate the radial gradients in age, metallcity and alpha-abundance. Generally, the galaxies in our sample have flat radial trends in age and [alpha/Fe], but negative gradients in [Z/H] (-0.20 +/- 0.05 dex). Combining our targets with two similar, long-slit studies to increase sample size, we find that the gradients are not correlated with the central velocity dispersion or K-band luminosity (both proxies for galaxy mass). However, we find that the age and metallicity gradients are both anti-correlated with their respective central values (to > 4 sigma), such that galaxies with young cores have steeper positive age gradients, and those with metal-rich centres have strong negative [Z/H] gradients.

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T. D. Rawle, Russell J. Smith, J. R. Lucey, A. M. Swinbank. 2008-07-22. Stellar population gradients in early-type cluster galaxies with VIMOS IFU. https://doi.org/10.1111/j.1365-2966.2008.13720.x

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