  We report Chandra ACIS-S3 x-ray imaging and spectroscopy of the R Aquarii
binary system that show a spatially resolved two-sided jet and an unresolved
central source. This is the first published report of such an x-ray jet seen in
an evolved stellar system comprised of ~2-3 solar masses. At E < 1 keV, the
x-ray jet extends both to the northeast and southwest relative to the central
binary system. At 1 < E < 7.1 keV, R Aqr is a point-like source centered on the
star system. While both 3.5-cm radio continuum emission and x-ray emission
appear coincident in projection and have maximum intensities at ~7.5" northeast
of the central binary system, the next strongest x-ray component is located
\~30" southwest of the central binary system and has no radio continuum
counterpart. The x-ray jets are likely shock heated in the recent past, and are
not in thermal equilibrium. The strongest southwest x-ray jet component may
have been shocked recently since there is no relic radio emission as expected
from an older shock. At the position of the central binary, we detect x-ray
emission below 1.6 keV consistent with blackbody emission at T ~2 x 10^6 K. At
the central star there is also a prominent 6.4 keV feature, a possible
fluorescence or collisionally excited Fe K-alpha line from an accretion disk or
from the wind of the giant star. For this excitation to occur, there must be an
unseen hard source of x-rays or particles in the immediate vicinity of the hot
star. Such a source would be hidden from view by the surrounding edge-on
accretion disk.
