A multiwavelength analysis of planetary nebulae in the Large Magellanic
  Cloud
  This paper examines, compares and plots optical, near- and mid-infrared (MIR)
photometric data for 605 planetary nebulae (PNe) in the Large Magellanic Cloud
(LMC). With the aid of multi-wavelength surveys such as the Spitzer legacy
programme Surveying the Agents of a Galaxy's Evolution, the Two Micron All Sky
Survey and the Magellanic Cloud Photometric Survey, plots have been constructed
to expose the relative contributions from molecular hydrogen, polycyclic
aromatic hydrocarbons, forbidden emission lines, warm dust continuum and
stellar emission at various bands. Besides identifying trends, these plots have
helped to reveal PN mimics including six previously known PNe in the outer LMC
which are re-classied as other object types. Together with continuing follow-up
optical observations, the data have enabled a substantial reduction in the
number of PNe previously tagged as `likely' and `possible'. The total number of
LMC PNe is adjusted to 715 but with a greater degree of confidence in regard to
classification.
  In each colour-colour plot, the more highly evolved LMC PNe are highlighted
for comparison with younger, brighter PNe. The faintest and most evolved PNe
typically cluster in areas of colour-colour space occupied by ordinary stars.
Possible reasons for the wide disparity in infrared colour-colour ratios, such
as evolution and dust composition, are presented for evaluation. A correlation
is found between the optical luminosity of PNe, emission-line ratios and the
MIR dust luminosity at various bands. Luminosity functions using the four
Infrared Array Camera and Multiband Imaging Photometer of Spitzer (MIPS) [24]
bands are directly compared, revealing an increasing accumulation of PNe within
the brightest two magnitudes at longer wavelengths. A correlation is also found
between the MIPS [24] band and the [O III] 5007 and H-beta fluxes.
