  We present a Chandra ACIS-S observation of the nuclear region of the nearby
spiral galaxy M51 (NGC 5194), which has a low-luminosity Seyfert 2 nucleus. The
X-ray image shows the nucleus, southern extranuclear cloud, and northern loop,
the morphology of the extended emission being very similar to those seen in
radio continuum and optical emission line images. The X-ray spectrum of the
nucleus is well represented by a model consisting of soft thermal plasma with
kT ~0.5 keV, a very hard continuum, and an Fe Kalpha emission line at 6.45 keV
with an equivalent width of >2 keV. The very strong Fe line and the flat
continuum indicate that the nucleus is obscured by a column density in excess
of 10^24 cm^-2 and the spectrum is dominated by reflected emission from cold
matter near the nucleus. The X-ray spectra of the extranuclear clouds are well
fitted by a thermal plasma model with kT ~0.5 keV. This spectral shape and
morphology strongly suggest that the clouds are shock heated by the bi-polar
outflow from the nucleus. The shock velocities of the extranuclear cloud and
northern loop inferred from the temperatures of the X-ray gas are 690 km/s and
660 km/s, respectively. By assuming a steady-state situation in which the
emission of the extranuclear clouds is powered by the jets, the mechanical
energy in the jets is found to be comparable to the bolometric luminosity of
the nucleus.
