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.