Feeding the Accretion Disk from the Dusty Torus in a Reddened Quasar
  We present here a detailed analysis of an unusual absorption line system in
the quasar SDSS J122826.79+100532.2. The absorption lines in the system have a
common redshifted velocity structure starting from $v\sim0$ and extending to
$\sim1,000\ \mathrm{km~s}^{-1}$, and are clearly detected in hydrogen Balmer
series up to H$\iota$, in metastable neutral helium triplet, and in optical
lines of excited states of single ionized iron. We estimated that the absorber
has a density $n_{\mathrm{H}}\approx10^{8.4}\ \mathrm{cm}^{-3}$ and an
ionization parameter $U\approx10^{-1.2}$, thereupon located it at
$r_{\mathrm{abs}}\approx1.5$ pc from the central supermassive black hole. The
inferred distance is remarkably similar to the evaporation radius for dust
grains $r_{\mathrm{evap}}\approx1$ pc in the quasar. Thus the absorber may be a
probe of an inflow starting from the dusty torus and feeding the accretion
disk. Both the featureless continuum and the broad emission lines are heavily
reddened with $E(B-V)\approx0.66$, in contrast to the narrow emission lines
whose reddening is negligible. The dusty medium could be located in between the
broad and narrow emission line regions, and possibly be associated with a
'cold' narrow absorption line system detected in \ion{Ca}{2} and \ion{Na}{1}
doublets nearly unshifted from the quasar systemic velocity. SDSS
J122826.79+100532.2 might represent such a rare case that both the inflow and
the torus could be tracked by absorption lines.
