Large-scale outflow in quasar LBQS J1206+1052:<i>HST</i>/<i>COS</i>observations

Using two orbits of HST/COS archival observations, we measure the location and energetics of a quasar outflow from LBQS J1206+1052. From separate collisional excitation models of observed N iii/N iii* and S iii/S iii* troughs, we measure the electron number density |$n_\mathrm{\scriptscriptstyle e}$| of the outflow. Both independent determinations are in full agreement and yield |$n_\mathrm{\scriptscriptstyle e} =10^{3.0}\, \mathrm{cm}^{-3}$|⁠. Combining this value of |$n_\mathrm{\scriptscriptstyle e}$| with photoionization simulations, we determine that the outflow is located 840 pc from the central source. The outflow has a velocity of 1400 km s−1, a mass flux of 9 M⊙ yr−1 and a kinetic luminosity of 1042.8 erg s−1. The distance finding is much larger than predicted from radiative acceleration models, but is consistent with recent empirical distance determinations.