The effects of dust on the derived photometric parameters of disks and
  bulges in spiral galaxies
  We present results of a study to quantify the effects of dust on the derived
photometric parameters of disks (old stellar disks and young stellar disks) and
bulges: disk scale-lengths, axis-ratios, central surface-brightness, bulge
effective radii and Sersic indexes. The changes in the derived photometric
parameters from their intrinsic values (as seen in the absence of dust) were
obtained by fitting simulated images of disks and bulges produced using
radiative transfer calculations and the model of Popescu et al. (2011). The
fits to the simulations were performed using GALFIT 3.0.2 data analysis
algorithm and the fitted models were the commonly used infinitely thin disks
described by exponential, general Sersic and de Vaucouleurs distributions. We
find the young stellar disks to suffer the most severe variation in the
photometric parameters due to dust effects. In this context we also present
corrections for narrow line (Balmer line) images. Old stellar disks are also
significantly affected by dust, in particular when fits are performed with
exponential functions. The photometric parameters of bulges are to a lesser
extent affected by dust. We also find that the variation of dust corrections
with face-on dust opacity and inclination is similar for bulges with different
intrinsic stellar emissivities (different Sersic index), with differences
manifesting only close to edge-on orientations of the disk. Dust corrections
for bulges are found to be insensitive to the choice of the truncation radius
and ellipticity of the bulge. All corrections are listed in the Appendix and
made available in electronic format.
