The location of the dust causing internal reddening of active galactic
  nuclei
  We use the Balmer decrements of the broad-line regions (BLRs) and narrow-line
regions (NLRs) of active galactic nuclei (AGNs) as reddening indicators to
investigate the location of the dust for four samples of AGNs with reliable
estimates of the NLR contribution to the Balmer lines. Intercomparison of the
NLR and BLR Balmer decrements indicates that the reddening of the NLR sets a
lower limit to the reddening of the BLR. Almost no objects have high NLR
reddening but low BLR reddening. The reddening of the BLR is often
substantially greater than the reddening of the NLR. The BLR reddening is
correlated with the equivalent widths of [O III] lines and the intensity of the
[O III] lines relative to broad H\beta. We find these relationships to be
consistent with the predictions of a simple model where the additional dust
reddening the BLR is interior to the NLR. We thus conclude that the dust
causing the additional reddening of the accretion disc and BLR is mostly
located at a smaller radius than the NLR.
