Comparison of the Diffuse Halpha and FUV Continuum Backgrounds: On the
  Origins of the Diffuse Halpha Background
  We compare the diffuse H$\alpha$ map of our Galaxy with the FUV
(1370-1710\AA) continuum map. The H$\alpha$ intensity correlates well with the
FUV intensity. The H$\alpha$/FUV intensity ratio increases in general with the
H$\alpha$ intensity and the FUV hardness ratio (1370-1520\AA\ to 1560-1710\AA),
implying that late OB stars may be the main source of the H$\alpha$
recombination line at high latitudes. The variation of the H$\alpha$ intensity
as a function of the Galactic latitude is also very similar to that of the FUV
intensity. The results likely suggest that not only the original radiation
sources of the H$\alpha$ and FUV backgrounds but also the radiative transfer
mechanisms responsible for the diffuse backgrounds are largely common.
Therefore, we propose a scenario wherein the H$\alpha$ background at high
latitudes is mostly composed of two components, H$\alpha$ photons produced by
in-situ recombination at the ionized regions around late OB stars and
dust-scattered light of the H$\alpha$ photons originating from late OB stars.
