The effects of dust on the photometric parameters of decomposed disks
  and bulges
  We present results of a study to quantify the effects of dust on the derived
photometric parameters of disk and bulges obtained from bulge-disk
decomposition: scale-length, effective radius, Sersic index, disk axis-ratio,
and bulge-to-disk ratio. The dust induced changes in these parameters were
obtained by fitting simulated images of composite systems (containing a disk
and a bulge) produced using radiative transfer calculations. The simulations
were fitted with the GALFIT 3.0.2 data analysis algorithm. Fits were done with
both a combination of an exponential plus a variable-index Sersic function as
well as with a combination of two variable-index Sersic functions. We find that
dust is biasing the derived exponential scale-length of decomposed disks
towards smaller values than would be otherwise derived if the galaxy were to
have no bulge. Similarly, the derived bulge-to-disk ratio is biased towards
smaller values. However, the derived axis-ratio of the disk is not changed in
the decomposition process. The derived effective radius of decomposed disks of
systems having exponential bulges is found to be less affected by dust when
fits are done with two variable-index Sersic functions. For the same type of
fits dust is found to bias the value of the derived effective radius of
decomposed disks towards lower values for systems having de Vaucouleurs bulges.
All corrections derived in this paper are made available in electronic form.
