The intrinsic reddening of the Magellanic Clouds as traced by background
  galaxies -- I. The bar and outskirts of the Small Magellanic Cloud
  We present a method to map the total intrinsic reddening of a foreground
extinguishing medium via the analysis of spectral energy distributions (SEDs)
of background galaxies. In this pilot study, we implement this technique in two
distinct regions of the Small Magellanic Cloud (SMC) - the bar and the southern
outskirts - using a combination of optical and near-infrared
$ugrizYJK_{\mathrm{s}}$ broadband imaging. We adopt the LePhare
$\chi^{2}$-minimisation SED-fitting routine and various samples of galaxies
and/or quasi-stellar objects to investigate the intrinsic reddening. We find
that only when we construct reddening maps using objects classified as galaxies
with low levels of intrinsic reddening (i.e. ellipticals/lenticulars and
early-type spirals), the resultant maps are consistent with previous literature
determinations i.e. the intrinsic reddening of the SMC bar is higher than that
in the outer environs. We employ two sets of galaxy templates - one theoretical
and one empirical - to test for template dependencies in the resulting
reddening maps and find that the theoretical templates imply systematically
higher reddening values by up to 0.20 mag in $E(B-V)$. A comparison with
previous reddening maps, based on the stellar components of the SMC, typically
shows reasonable agreement. There is, however, significant variation amongst
the literature reddening maps as to the level of intrinsic reddening associated
with the bar. Thus, it is difficult to unambiguously state that instances of
significant discrepancies are the result of appreciable levels of dust not
accounted for in some literature reddening maps or whether they reflect issues
with our adopted methodology.
