Galaxy And Mass Assembly (GAMA): Galaxy colour gradients versus colour,
  structure and luminosity
  Using single-component fits to SDSS/UKIDSS images of galaxies in the G09
region of the GAMA survey we study radial colour gradients across the galaxy
population. We use the multiwavelength information provided by MegaMorph
analysis of galaxy light profiles to calculate intrinsic colour gradients, and
divide into six subsamples split by overall S\'{e}rsic index ($n$) and galaxy
colour. We find a bimodality in the colour gradients of high- and low-$n$
galaxies in all wavebands, which varies with overall galaxy luminosity. Global
trends in colour gradients therefore result from combining the contrasting
behaviour of a number of different galaxy populations. The ubiquity of strong
negative colour gradients supports the picture of inside-out growth through gas
accretion for blue, low-$n$ galaxies, and through dry minor mergers for red,
high-$n$ galaxies. An exception is the blue high-n population, with properties
indicative of dissipative major mergers.
