Discovery of a damped Ly$\alpha$ absorber originating in a spectacular
  interacting dwarf galaxy pair at $z = 0.026$
  We present the discovery of neutral gas detected in both damped Ly$\alpha$
absorption (DLA) and HI 21-cm emission outside of the stellar body of a galaxy,
the first such detection in the literature. A joint analysis between the Cosmic
Ultraviolet Baryon Survey and the MeerKAT Absorption Line Survey reveals an HI
bridge connecting two interacting dwarf galaxies
(log$(M_{\text{star}}/\text{M}_{\odot}) = 8.5 \pm 0.2$) that host a $z = 0.026$
DLA with log[$N$(HI)/cm$^{-2}$]$ = 20.60 \pm 0.05$ toward the QSO J2339-5523
($z_{\text{QSO}} = 1.35$). At impact parameters of $d = 6$ and $33$ kpc, the
dwarf galaxies have no companions more luminous than $\approx 0.05L_{*}$ within
at least $\Delta v = \pm 300$ km s$^{-1}$ and $d \approx 350$ kpc. HI 21-cm
emission is spatially coincident with the DLA at the 2-3$\sigma$ level per
spectral channel over several adjacent beams. However, HI 21-cm absorption is
not detected against the radio-bright QSO; if the background UV and radio
sources are spatially aligned, the gas is either warm or clumpy (with spin
temperature to covering factor ratio $T_{s}/f_{c} > 1880$ K). VLT-MUSE
observations demonstrate that the $\alpha$-element abundance of the ionized ISM
is consistent with the DLA ($\approx 10$% solar), suggesting that the neutral
gas envelope is perturbed ISM gas. This study showcases the impact of
dwarf-dwarf interactions on the physical and chemical state of neutral gas
outside of star-forming regions. In the SKA era, joint UV and HI 21-cm analyses
will be critical for connecting the cosmic neutral gas content to galaxy
environments.
