Quasar Outflow Contribution to AGN Feedback: Observations of QSO SDSS
  J0838+2955
  We present a detailed analysis of the Astrophysical Research Consortium 3.5 m
telescope spectrum of QSO SDSS J0838+2955. The object shows three broad
absorption line (BAL) systems at 22,000, 13,000, and 4900 km s^-1 blueshifted
from the systemic redshift of z=2.043. Of particular interest is the lowest
velocity system that displays absorption from low-ionization species such as Mg
II, Al II, Si II, Si II*, Fe II and Fe II*. Accurate column densities were
measured for all transitions in this lowest velocity BAL using an inhomogeneous
absorber model. The ratio of column densities of Si II* and Fe II* with respect
to their ground states gave an electron number density of log n_e (cm^-3) =
3.75 +/- 0.22 for the outflow. Photoionization modeling with careful regards to
chemical abundances and the incident spectral energy distribution predicts an
ionization parameter of log U_H = -1.93 +/- 0.21 and a hydrogen column density
of log N_H (cm^-2) = 20.80 +/- 0.28. This places the outflow at 3.3+1.5-1.0 kpc
from the central AGN. Assuming that the fraction of solid angle subtended by
the outflow is 0.2, these values yield a kinetic luminosity of (4.5+3.1-1.8) x
10^45 erg s^-1, which is (1.4+1.1-0.6)% the bolometric luminosity of the QSO
itself. Such large kinetic luminosity suggests that QSO outflows are a major
contributor to AGN feedback mechanisms.
