The Baltimore Oriole's Nest: Cool Winds from the Inner and Outer Parts
  of a Star-Forming Galaxy at z=1.3
  Strong galactic winds are ubiquitous at $z\gtrsim 1$. However, it is not well
known where inside galaxies these winds are launched from. We study the cool
winds ($\sim 10^4$\,K) in two spatial regions of a massive galaxy at $z=1.3$,
which we nickname the "Baltimore Oriole's Nest." The galaxy has a stellar mass
of $10^{10.3\pm 0.3} M_\odot$, is located on the star-forming main sequence,
and has a morphology indicative of a recent merger. Gas kinematics indicate a
dynamically complex system with velocity gradients ranging from 0 to 60
$\mathrm{km}\cdot\mathrm{s}^{-1}$. The two regions studied are: a dust-reddened
center (Central region), and a blue arc at 7 kpc from the center (Arc region).
We measure the \ion{Fe}{2} and \ion{Mg}{2} absorption line profiles from deep
Keck/DEIMOS spectra. Blueshifted wings up to 450 km$\cdot$s$^{-1}$ are found
for both regions. The \ion{Fe}{2} column densities of winds are $10^{14.7\pm
0.2}\,\mathrm{cm}^{-2}$ and $10^{14.6\pm 0.2}\,\mathrm{cm}^{-2}$ toward the
Central and Arc regions, respectively. Our measurements suggest that the winds
are most likely launched from both regions. The winds may be driven by the
spatially extended star formation, the surface density of which is around 0.2
$M_\odot\,\mathrm{yr}^{-1}\cdot \mathrm{kpc}^{-2}$ in both regions. The mass
outflow rates are estimated to be $4\,M_\odot\,\mathrm{yr}^{-1}$ and
$3\,M_\odot\,\mathrm{yr}^{-1}$ for the Central and Arc regions, with
uncertainties of one order-of-magnitude or more. Findings of this work and a
few previous studies suggest that the cool galactic winds at $z\gtrsim 1$ might
be commonly launched from the entire spatial extents of their host galaxies due
to extended galaxy star formation.
