Galaxy And Mass Assembly (GAMA): The Bright Void Galaxy Population in
  the Optical and Mid-IR
  We examine the properties of galaxies in the Galaxies and Mass Assembly
(GAMA) survey located in voids with radii $>10~h^{-1}$ Mpc. Utilising the GAMA
equatorial survey, 592 void galaxies are identified out to z~0.1 brighter than
$M_{r} = -18.4$, our magnitude completeness limit. Using the $W_{\rm{H\alpha}}$
vs. [NII]/H$\alpha$ (WHAN) line strength diagnostic diagram, we classify their
spectra as star forming, AGN, or dominated by old stellar populations. For
objects more massive than $5\times10^{9}$ M$_{\odot}$, we identify a sample of
26 void galaxies with old stellar populations classed as passive and retired
galaxies in the WHAN diagnostic diagram, else they lack any emission lines in
their spectra. When matched to WISE mid-IR photometry, these passive and
retired galaxies exhibit a range of mid-IR colour, with a number of void
galaxies exhibiting [4.6]-[12] colours inconsistent with completely quenched
stellar populations, with a similar spread in colour seen for a randomly drawn
non-void comparison sample. We hypothesise that a number of these galaxies host
obscured star formation, else they are star forming outside of their central
regions targeted for single fibre spectroscopy. When matched to a randomly
drawn sample of non-void galaxies, the void and non-void galaxies exhibit
similar properties in terms of optical and mid-IR colour, morphology, and star
formation activity, suggesting comparable mass assembly and quenching
histories. A trend in mid-IR [4.6]-[12] colour is seen, such that both void and
non-void galaxies with quenched/passive colours <1.5 typically have masses
higher than $10^{10}$ M$_{\odot}$, where internally driven processes play an
increasingly important role in galaxy evolution.
