HST/COS Observations of Quasar Outflows in the 500 -- 1050 \AA\ Rest
  Frame: VI Wide, Energetic Outflows in SDSS J0755+2306
  We present the analysis of two outflows (S1 at --5500 km s$^{-1}$ and S2 at
--9700 km s$^{-1}$) seen in recent HST/COS observations of quasar SDSS
J0755+2306 (z = 0.854). The outflows are detected as absorption troughs from
both high-ionization species, including N III, O III, and S IV, and very
high-ionization species, including Ar VIII, Ne VIII, and Na IX. The derived
photoionization solutions show that each outflow requires a two
ionization-phase solution. For S1, troughs from S IV* and S IV allow us to
derive an electron number density, $n_{e}$ = 1.8$\times$10$^4$ cm$^{-3}$, and
its distance from the central source of $R$ = 270 pc. For S2, troughs from O
III* and O III yield $n_{e}$ = 1.2$\times$10$^3$ cm$^{-3}$ and $R$ = 1600 pc.
The kinetic luminosity of S2 is $>$ 12% of the Eddington luminosity for the
quasar and therefore can provide strong AGN feedback effects. Comparison of
absorption troughs from O III and O VI in both outflow systems supports the
idea that for a given element, higher ionization ions have larger covering
fractions than lower ionization ones.
