Determining the extragalactic extinction law with SALT. II. Additional
  sample
  We present new results from an on-going programme to study the dust
extragalactic extinction law in E/S0 galaxies with dust lanes with the Southern
African Large Telescope (SALT) during its performance-verification phase. The
wavelength dependence of the dust extinction for seven galaxies is derived in
six spectral bands ranging from the near-ultraviolet atmospheric cutoff to the
near-infrared. The derivation of an extinction law is performed by fitting
model galaxies to the unextinguished parts of the image in each spectral band,
and subtracting from these the actual images. We compare our results with the
derived extinction law in the Galaxy and find them to run parallel to the
Galactic extinction curve with a mean total-to-selective extinction value of
2.71+-0.43. We use total optical extinction values to estimate the dust mass
for each galaxy, compare these with dust masses derived from IRAS measurements,
and find them to range from 10^4 to 10^7 Solar masses. We study the case of the
well-known dust-lane galaxy NGC2685 for which HST/WFPC2 data is available to
test the dust distribution on different scales. Our results imply a scale-free
dust distribution across the dust lanes, at least within ~1 arcsec (~60 pc)
regions.
