Characterizing Dust Attenuation in Local Star Forming Galaxies: UV and
  Optical Reddening
  The dust attenuation for a sample of $\sim$10000 local ($z\lesssim0.1$) star
forming galaxies is constrained as a function of their physical properties. We
utilize aperture-matched multi-wavelength data available from the Galaxy
Evolution Explorer (GALEX) and the Sloan Digital Sky Survey (SDSS) to ensure
that regions of comparable size in each galaxy are being analyzed. We follow
the method of Calzetti et al. (1994) and characterize the dust attenuation
through the UV power-law index, $\beta$, and the dust optical depth, which is
quantified using the difference in Balmer emission line optical depth,
$\tau_B^l=\tau_{\mathrm{H}\beta} - \tau_{\mathrm{H}\alpha}$. The observed
linear relationship between $\beta$ and $\tau_B^l$ is similar to the local
starburst relation, but the large scatter ($\sigma_{\mathrm{int}}=0.44$)
suggests there is significant variation in the local Universe. We derive a
selective attenuation curve over the range
$1250\mathrm{\AA}<\lambda<8320\mathrm{\AA}$ and find that a single attenuation
curve is effective for characterizing the majority of galaxies in our sample.
This curve has a slightly lower selective attenuation in the UV compared to
previously determined curves. We do not see evidence to suggest that a 2175\AA\
feature is significant in the average attenuation curve. Significant positive
correlations are seen between the amount of UV and optical reddening and galaxy
metallicity, mass, star formation rate (SFR), and SFR surface density. This
provides a potential tool for gauging attenuation where the stellar population
is unresolved, such as at high-$z$.
