Fingerprints of Galactic Loop I on the Cosmic Microwave Background
  We investigate possible imprints of galactic foreground structures such as
the "radio loops" in the derived maps of the cosmic microwave background.
Surprisingly there is evidence for these not only at radio frequencies through
their synchrotron radiation, but also at microwave frequencies where emission
by dust dominates. This suggests the mechanism is magnetic dipole radiation
from dust grains enriched by metallic iron or ferrimagnetic materials. This new
foreground we have identified is present at high galactic latitudes, and
potentially dominates over the expected $B$-mode polarization signal due to
primordial gravitational waves from inflation.
