A Unified Model of the Fermi Bubbles, Microwave Haze, and Polarized
  Radio Lobes: Reverse Shocks in the Galactic Center's Giant Outflows
  The Galactic Center's giant outflows are manifest in three different,
non-thermal phenomena: i) the hard-spectrum, \gamma-ray `Fermi Bubbles'
emanating from the nucleus and extending to |b| ~ 50 degrees; ii) the
hard-spectrum, total-intensity microwave (~ 20-40 GHz) `Haze' extending to |b|
~ 35 degrees in the lower reaches of the Fermi Bubbles; and iii) the steep
spectrum, polarized, `S-PASS' radio (~ 2-20 GHz) Lobes that envelop the Bubbles
and extend to |b| ~ 60 degrees. We find that the nuclear outflows inflate a
genuine bubble in each Galactic hemisphere that has the classical structure,
working outwards, of reverse shock, contact discontinuity, and forward shock.
Expanding into the finite pressure of the halo and given appreciable cooling
and gravitational losses, the contact discontinuity of each bubble is now
expanding only very slowly. We find observational signatures in both
hemispheres of giant, reverse shocks at heights of ~ 1 kpc above the nucleus;
their presence ultimately explains all three of the non-thermal phenomena
mentioned above. Synchrotron emission from shock-reaccelerated cosmic-ray
electrons explains the spectrum, morphology, and vertical extent of the
microwave Haze and the polarized radio Lobes. Collisions between
shock-reaccelerated hadrons and denser gas in cooling condensations that form
inside the contact discontinuity account for most of the Bubbles' \gamma-ray
emissivity.
