An Extreme Metallicity, Large-Scale Outflow from a Star-Forming Galaxy
  at z ~ 0.4
  We present a detailed analysis of a large-scale galactic outflow in the CGM
of a massive (M_h ~ 10^12.5 Msun), star-forming (6.9 Msun/yr), sub-L* (0.5
L_B*) galaxy at z=0.39853 that exhibits a wealth of metal-line absorption in
the spectra of the background quasar Q 0122-003 at an impact parameter of 163
kpc. The galaxy inclination angle (i=63 degree) and the azimuthal angle (Phi=73
degree) imply that the QSO sightline is passing through the projected
minor-axis of the galaxy. The absorption system shows a multiphase,
multicomponent structure with ultra-strong, wide velocity spread OVI (logN =
15.16\pm0.04, V_{90} = 419 km/s) and NV (logN = 14.69\pm0.07, V_{90} = 285
km/s) lines that are extremely rare in the literature. The highly ionized
absorption components are well explained as arising in a low density (10^{-4.2}
cm^{-3}), diffuse (10 kpc), cool (10^4 K) photoionized gas with a super-solar
metallicity ([X/H] > 0.3). From the observed narrowness of the Lyb profile, the
non-detection of SIV absorption, and the presence of strong CIV absorption we
rule out equilibrium/non-equilibrium collisional ionization models. The
low-ionization photoionized gas with a density of 10^{-2.5} cm^{-3} and a
metallicity of [X/H] > -1.4 is possibly tracing recycled halo gas. We estimate
an outflow mass of ~2x10^{10} Msun, a mass-flow rate of ~54 Msun/yr, a kinetic
luminosity of ~9x10^{41} erg/s, and a mass loading factor of ~8 for the
outflowing high-ionization gas. These are consistent with the properties of
"down-the-barrel" outflows from infrared-luminous starbursts as studied by
Rupke et al. Such powerful, large-scale, metal-rich outflows are the primary
means of sufficient mechanical and chemical feedback as invoked in theoretical
models of galaxy formation and evolution.
