Galaxy And Mass Assembly (GAMA): mass-size relations of z$<$0.1 galaxies
  subdivided by S\'ersic index, colour and morphology
  We use data from the Galaxy And Mass Assembly (GAMA) survey in the redshift
range 0.01$<$z$<$0.1 (8399 galaxies in $g$ to $K_s$ bands) to derive the
stellar mass $-$ half-light radius relations for various divisions of 'early'
and 'late'-type samples. We find the choice of division between early and late
(i.e., colour, shape, morphology) is not particularly critical, however, the
adopted mass limits and sample selections (i.e., the careful rejection of
outliers and use of robust fitting methods) are important. In particular we
note that for samples extending to low stellar mass limits
($<10^{10}\mathcal{M_{\odot}}$) the S\'ersic index bimodality, evident for high
mass systems, becomes less distinct and no-longer acts as a reliable separator
of early- and late-type systems. The final set of stellar mass $-$ half-light
radius relations are reported for a variety of galaxy population subsets in 10
bands ($ugrizZYJHK_s$) and are intended to provide a comprehensive low-z
benchmark for the many ongoing high-z studies. Exploring the variation of the
stellar mass $-$ half-light radius relations with wavelength we confirm earlier
findings that galaxies appear more compact at longer wavelengths albeit at a
smaller level than previously noted: at $10^{10}\mathcal{M_{\odot}}$ both
spiral systems and ellipticals show a decrease in size of 13% from $g$ to $K_s$
(which is near linear in log wavelength). Finally we note that the sizes used
in this work are derived from 2D S\'ersic light profile fitting (using
GALFIT3), i.e., elliptical semi-major half light radii, improving on earlier
low-z benchmarks based on circular apertures.
