Get access

Galaxy And Mass Assembly (GAMA): Structural Investigation of Galaxies via Model Analysis

Authors

  • Lee S. Kelvin,

    Corresponding author
    1. School of Physics and Astronomy, University of St Andrews, North Haugh, St. Andrews, Fife KY16 9SS
    2. International Centre for Radio Astronomy Research, 7 Fairway, The University of Western Australia, Crawley, Perth, WA 6009, Australia
    Search for more papers by this author
  • Simon P. Driver,

    1. School of Physics and Astronomy, University of St Andrews, North Haugh, St. Andrews, Fife KY16 9SS
    2. International Centre for Radio Astronomy Research, 7 Fairway, The University of Western Australia, Crawley, Perth, WA 6009, Australia
    Search for more papers by this author
  • Aaron S. G. Robotham,

    1. School of Physics and Astronomy, University of St Andrews, North Haugh, St. Andrews, Fife KY16 9SS
    2. International Centre for Radio Astronomy Research, 7 Fairway, The University of Western Australia, Crawley, Perth, WA 6009, Australia
    Search for more papers by this author
  • David T. Hill,

    1. School of Physics and Astronomy, University of St Andrews, North Haugh, St. Andrews, Fife KY16 9SS
    Search for more papers by this author
  • Mehmet Alpaslan,

    1. School of Physics and Astronomy, University of St Andrews, North Haugh, St. Andrews, Fife KY16 9SS
    2. International Centre for Radio Astronomy Research, 7 Fairway, The University of Western Australia, Crawley, Perth, WA 6009, Australia
    Search for more papers by this author
  • Ivan K. Baldry,

    1. Astrophysics Research Institute, Liverpool John Moores University, Twelve Quays House, Egerton Wharf, Birkenhead CH41 1LD
    Search for more papers by this author
  • Steven P. Bamford,

    1. The Centre for Astronomy and Particle Theory, The School of Physics and Astronomy, University of Nottingham, University Park, Nottingham NG7 2RD
    Search for more papers by this author
  • Joss Bland-Hawthorn,

    1. Sydney Institute for Astronomy, School of Physics A28, University of Sydney, NSW 2006, Australia
    Search for more papers by this author
  • Sarah Brough,

    1. Australian Astronomical Observatory, PO Box 296, Epping, NSW 1710, Australia
    Search for more papers by this author
  • Alister W. Graham,

    1. Centre for Astrophysics and Supercomputing, Swinburne University of Technology, Hawthorn, VIC 3122, Australia
    Search for more papers by this author
  • Boris Häussler,

    1. The Centre for Astronomy and Particle Theory, The School of Physics and Astronomy, University of Nottingham, University Park, Nottingham NG7 2RD
    Search for more papers by this author
  • Andrew M. Hopkins,

    1. Australian Astronomical Observatory, PO Box 296, Epping, NSW 1710, Australia
    Search for more papers by this author
  • Jochen Liske,

    1. European Southern Observatory, Karl-Schwarzschild-Str. 2, 85748 Garching, Germany
    Search for more papers by this author
  • Jon Loveday,

    1. Astronomy Centre, University of Sussex, Falmer, Brighton BN1 9QH
    Search for more papers by this author
  • Peder Norberg,

    1. Institute for Computational Cosmology, Department of Physics, Durham University, South Road, Durham DH1 3LE
    Search for more papers by this author
  • Steven Phillipps,

    1. Astrophysics Group, H.H. Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol BS8 1TL
    Search for more papers by this author
  • Cristina C. Popescu,

    1. Jeremiah Horrocks Institute, University of Central Lancashire, Preston PR1 2HE
    Search for more papers by this author
  • Matthew Prescott,

    1. Astrophysics Research Institute, Liverpool John Moores University, Twelve Quays House, Egerton Wharf, Birkenhead CH41 1LD
    Search for more papers by this author
  • Edward N. Taylor,

    1. Sydney Institute for Astronomy, School of Physics A28, University of Sydney, NSW 2006, Australia
    2. School of Physics, The University of Melbourne, Parkville, VIC 3010, Australia
    Search for more papers by this author
  • Richard J. Tuffs

    1. Max-Planck-Institut fuer Kernphysik, Saupfercheckweg 1, D-69117 Heidelberg, Germany
    Search for more papers by this author

E-mail: lee.kelvin@st-andrews.ac.uk

ABSTRACT

We present single-Sérsic two-dimensional (2D) model fits to 167 600 galaxies modelled independently in the ugrizYJHK bandpasses using reprocessed Sloan Digital Sky Survey Data Release Seven (SDSS DR7) and UKIRT Infrared Deep Sky Survey Large Area Survey imaging data available from the Galaxy And Mass Assembly (GAMA) data base. In order to facilitate this study we developed Structural Investigation of Galaxies via Model Analysis (sigma), an r wrapper around several contemporary astronomy software packages including source extractor, psf extractor and galfit 3. sigma produces realistic 2D model fits to galaxies, employing automatic adaptive background subtraction and empirical point spread function measurements on the fly for each galaxy in GAMA. Using these results, we define a common coverage area across the three GAMA regions containing 138 269 galaxies. We provide Sérsic magnitudes truncated at 10re which show good agreement with SDSS Petrosian and GAMA photometry for low Sérsic index systems (n < 4), and much improved photometry for high Sérsic index systems (n > 4), recovering as much as Δm= 0.5 mag in the r band. We employ a K-band Sérsic index/ur colour relation to delineate the massive (n > ∼2) early-type galaxies (ETGs) from the late-type galaxies (LTGs). The mean Sérsic index of these ETGs shows a smooth variation with wavelength, increasing by 30 per cent from g through K. LTGs exhibit a more extreme change in Sérsic index, increasing by 52 per cent across the same range. In addition, ETGs and LTGs exhibit a 38 and 25 per cent decrease, respectively, in half-light radius from g through K. These trends are shown to arise due to the effects of dust attenuation and stellar population/metallicity gradients within galaxy populations.

Ancillary