A Cautionary Tale of Attenuation in Star Forming Regions
  The attenuation of light in star forming galaxies is correlated with a
multitude of physical parameters including star formation rate, metallicity and
total dust content. This variation in attenuation is even more prevalent on the
kiloparsec scale, which is relevant to many current spectroscopic integral
field unit surveys. To understand the cause of this variation, we present and
analyse \textit{Swift}/UVOT near-UV (NUV) images and SDSS/MaNGA emission-line
maps of 29 nearby ($z<0.084$) star forming galaxies. We resolve
kiloparsec-sized star forming regions within the galaxies and compare their
optical nebular attenuation (i.e., the Balmer emission line optical depth,
$\tau^l_B\equiv\tau_{\textrm{H}\beta}-\tau_{\textrm{H}\alpha}$) and NUV stellar
continuum attenuation (via the NUV power-law index, $\beta$) to the attenuation
law described by Battisti et al. The data agree with that model, albeit with
significant scatter. We explore the dependence of the scatter of the
$\beta$-$\tau^l_B$ measurements from the star forming regions on different
physical parameters, including distance from the nucleus, star formation rate
and total dust content. Finally, we compare the measured $\tau^l_B$ and $\beta$
between the individual star forming regions and the integrated galaxy light. We
find a strong variation in $\beta$ between the kiloparsec scale and the larger
galaxy scale not seen in $\tau^l_B$. We conclude that the sight-line dependence
of UV attenuation and the reddening of $\beta$ due to the light from older
stellar populations could contribute to the $\beta$-$\tau^l_B$ discrepancy.
