Please use this identifier to cite or link to this item: http://hdl.handle.net/1959.3/216358

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Title

The 6dF Galaxy Survey: stellar population trends across and through the Fundamental Plane

Author(s)

Springob, Christopher M.;  Magoulas, Christina;  Proctor, Rob;  Colless, Matthew;  Jones, D. Heath;  Kobayashi, Chiaki;  Campbell, Lachlan;  Lucey, John;  Mould, Jeremy

Abstract

We present results from an analysis of stellar population parameters for 7132 galaxies in the 6dF Galaxy Survey Fundamental Plane (FP) sample. We bin the galaxies along the axes, v 1, v 2 and v 3, of the tri-variate Gaussian to which we have fitted the galaxy distribution in effective radius, surface brightness and central velocity dispersion (FP space), and compute median values of stellar age, [Fe/H], [Z/H] and [α/Fe]. We determine the directions of the vectors in FP space along which each of the binned stellar population parameters vary most strongly. In contrast to previous work, we find stellar population trends not just with velocity dispersion and FP residual, but with radius and surface brightness as well. The most remarkable finding is that the stellar population parameters vary through the plane (v 1 direction) and across the plane (v 3 direction), but show no variation at all along the plane (v 2 direction). The v 2 direction in FP space roughly corresponds to 'luminosity density'. We interpret a galaxy's position along this vector as being closely tied to its merger history, such that early-type galaxies with lower luminosity density are more likely to have undergone major mergers. This conclusion is reinforced by an examination of the simulations of Kobayashi, which show clear trends of merger history with v 2.

Publication type

Journal article

Research centre

Swinburne University of Technology. Faculty of Information and Communication Technologies. Centre for Astrophysics and Supercomputing

Source

Monthly Notices of the Royal Astronomical Society, Vol. 420, no. 4 (Mar 2012), pp. 2773-2784

Publication year

2012

FOR Code(s)

0201 Astronomical and Space Sciences

Keyword(s)

Elliptical galaxies;  Fundamental parameters;  Fundamental Plane;  Galaxy evolution;  Galaxy structure;  Lenticular galaxies

Publisher

Wiley-Blackwell

ISSN

0035-8711

Publisher URL

http://dx.doi.org/10.1111/j.1365-2966.2011.19900.x

Copyright

Copyright © 2012 The Authors. Journal copyright © 2012 Royal Astronomical Society. The accepted manuscript is reproduced in accordance with the copyright policy of the publisher. The definitive publication is available at www.interscience.wiley.com.

Research Projects

The 6dF galaxy survey: mass and motions in the nearby universe, Australian Research Council grant number DP0208876

Additional information

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Full text

Peer reviewed