  We study the possibility that the gamma ray emission in the Fermi bubbles
observed is produced by cosmic ray electrons with a spectrum similar to
Galactic cosmic rays. We argue that the cosmic ray electrons steepen near 1 TeV
from $E^{-3}$ to about $E^{-4.2}$, and are partially secondaries derived from
the knee-feature of normal cosmic rays. We speculate that the observed feature
at $\sim 130$ GeV could essentially be due to inverse Compton emission off a
pair-production peak on top of a turn-off in the $\gamma$ ray spectrum at $\sim
130$ GeV. It suggests that the knee of normal cosmic rays is the same
everywhere in the Galaxy. A consequence could be that all supernovae
contributing give the same cosmic ray spectrum, with the knee feature given by
common stellar properties; in fact, this is consistent with the supernova
theory proposed by Bisnovatyi-Kogan (1970), a magneto-rotational mechanism, if
massive stars converge to common properties in terms of rotation and magnetic
fields just before they explode.
