A far-IR view of the starburst driven superwind in NGC 2146
  NGC 2146, a nearby luminous infrared galaxy (LIRG), presents evidence for
outflows along the disk minor axis in all gas phases (ionized, neutral atomic
and molecular). We present an analysis of the multi-phase starburst driven
superwind in the central 5 kpc as traced in spatially resolved spectral line
observations, using far-IR Herschel PACS spectroscopy, to probe the effects on
the atomic and ionized gas, and optical integral field spectroscopy to examine
the ionized gas through diagnostic line ratios. We observe an increased ~250
km/s velocity dispersion in the [OI] 63 micron, [OIII] 88 micron, [NII] 122
micron and [CII] 158 micron fine-structure lines that is spatially coincident
with high excitation gas above and below the disk. We model this with a slow
~200 km/s shock and trace the superwind to the edge of our field of view 2.5
kpc above the disk. We present new SOFIA 37 micron observations to explore the
warm dust distribution, and detect no clear dust entrainment in the outflow.
The stellar kinematics appear decoupled from the regular disk rotation seen in
all gas phases, consistent with a recent merger event disrupting the system. We
consider the role of the superwind in the evolution of NGC 2146 and speculate
on the evolutionary future of the system. Our observations of NGC 2146 in the
far-IR allow an unobscured view of the wind, crucial for tracing the superwind
to the launching region at the disk center, and provide a local analog for
future ALMA observations of outflows in high redshift systems.
