Galaxy And Mass Assembly (GAMA): Understanding the wavelength dependence
  of galaxy structure with bulge-disc decompositions
  With a large sample of bright, low-redshift galaxies with optical$-$near-IR
imaging from the GAMA survey we use bulge-disc decompositions to understand the
wavelength-dependent behavior of single-S\'ersic structural measurements.
  We denote the variation in single-S\'ersic index with wavelength as
$\mathcal{N}$, likewise for effective radius we use $\mathcal{R}$. We find that
most galaxies with a substantial disc, even those with no discernable bulge,
display a high value of $\mathcal{N}$. The increase in S\'ersic index to longer
wavelengths is therefore intrinsic to discs, apparently resulting from radial
variations in stellar population and/or dust reddening. Similarly, low values
of $\mathcal{R}$ ($<$ 1) are found to be ubiquitous, implying an element of
universality in galaxy colour gradients.
  We also study how bulge and disc colour distributions vary with galaxy type.
We find that, rather than all bulges being red and all discs being blue in
absolute terms, both components become redder for galaxies with redder total
colours. We even observe that bulges in bluer galaxies are typically bluer than
discs in red galaxies, and that bulges and discs are closer in colour for
fainter galaxies. Trends in total colour are therefore not solely due to the
colour or flux dominance of the bulge or disc.
