GAMA/H-ATLAS: The ultraviolet spectral slope and obscuration in galaxies
  We use multiwavelength data from the Galaxy And Mass Assembly (GAMA) and
Herschel ATLAS (H-ATLAS) surveys to compare the relationship between various
dust obscuration measures in galaxies. We explore the connections between the
ultraviolet (UV) spectral slope, $\beta$, the Balmer decrement, and the far
infrared (IR) to $150\,$nm far ultraviolet (FUV) luminosity ratio. We explore
trends with galaxy mass, star formation rate (SFR) and redshift in order to
identify possible systematics in these various measures. We reiterate the
finding of other authors that there is a large scatter between the Balmer
decrement and the $\beta$ parameter, and that $\beta$ may be poorly constrained
when derived from only two broad passbands in the UV. We also emphasise that
FUV derived SFRs, corrected for dust obscuration using $\beta$, will be
overestimated unless a modified relation between $\beta$ and the attenuation
factor is used. Even in the optimum case, the resulting SFRs have a significant
scatter, well over an order of magnitude. While there is a stronger correlation
between the IR to FUV luminosity ratio and $\beta$ parameter than with the
Balmer decrement, neither of these correlations are particularly tight, and
dust corrections based on $\beta$ for high redshift galaxy SFRs must be treated
with caution. We conclude with a description of the extent to which the
different obscuration measures are consistent with each other as well as the
effects of including other galactic properties on these correlations.
