Chandra X-Ray Observations of Two Unusual BAL Quasars
  We report sensitive Chandra X-ray non-detections of two unusual, luminous
Iron Low-Ionization Broad Absorption Line Quasars (FeLoBALs). The observations
do detect a non-BAL, wide-binary companion quasar to one of the FeLoBAL
quasars. We combine X-ray-derived column density lower limits (assuming solar
metallicity) with column densities measured from ultraviolet spectra and CLOUDY
photoionization simulations to explore whether constant density slabs at broad
line region densities can match the physical parameters of these two BAL
outflows, and find that they cannot. In the "overlapping-trough" object SDSS
J0300+0048, we measure the column density of the X-ray absorbing gas to be N_H
>= 1.8 x 1024 cm-2. From the presence of Fe II UV78 absorption but lack of Fe
II UV195/UV196 absorption, we infer the density in that part of the absorbing
region to be n_e ~ 106 cm-3. We do find that a slab of gas at that density
might be able to explain this object's absorption. In the Fe III-dominant
object SDSS J2215-0045, the X-ray absorbing column density of N_H >= 3.4 x 1024
cm-2 is consistent with the Fe III-derived N_H >= 2 x 1022 cm-2 provided the
ionization parameter is log U > 1.0 for both the n_e = 1011 cm-3 and n_e = 1012
cm-3 scenarios considered (such densities are required to produce Fe III
absorption without Fe II absorption). However, the velocity width of the
absorption rules out its being concentrated in a single slab at these
densities. Instead, this object's spectrum can be explained by a low density,
high ionization and high temperature disk wind that encounters and ablates
higher density, lower ionization Fe III-emitting clumps.
