  Low-ionization Broad Absorption Line QSOs (LoBALs) are suspected to be
merging systems in which extreme, AGN-driven outflows have been triggered.
Whether or not LoBALs are uniquely associated with mergers, however, has yet to
be established. To characterize the morphologies of LoBALs, we present the
first high-resolution morphological analysis of a volume-limited sample of 22
SDSS-selected LoBALs at 0.5 < z < 0.6 from Hubble Space Telescope Wide Field
Camera 3 observations. Host galaxies are resolved in 86% of the systems in
F125W, which is sensitive to old stellar populations, while only 18% are
detected in F475W, which traces young, unobscured stellar populations. Signs of
recent or ongoing tidal interaction are present in 45-64% of the hosts,
including double nuclei, tidal tails, bridges, plumes, shells, and extended
debris. Ongoing interaction with a companion is apparent in 27-41% of the
LoBALs, with as much as 1/3 of the sample representing late-stage mergers at
projected nuclear separations <10 kpc. Detailed surface brightness modeling
indicates that 41% of the hosts are bulge-dominated while only 18% are disks.
We discuss trends in various properties as a function of merger stage and
parametric morphology. Notably, mergers are associated with slower, dustier
winds than those seen in undisturbed/unresolved hosts. Our results favor an
evolutionary scenario in which quasar-level accretion during various merger
stages is associated with the observed outflows in low-z LoBALs. We discuss
differences between LoBALs and FeLoBALs and show that selection via the
traditional Balnicity index would have excluded all but one of the mergers.
