  We utilize the complimentary capabilities of XMM-Newton and Chandra, to
conduct a detailed imaging and spectral study of the nearby galaxy NGC 4945
focussing on its nucleus and immediate surroundings (within ~1 kpc of the
nucleus). A complex morphology is revealed including a predominantly hard, but
partially resolved, nuclear source plus a spectrally soft, conically shaped
X-ray "plume", which extends 30" (500 pc) to the northwest. In NGC 4945 our
direct view of the active galactic nucleus (AGN) is blocked below ~10 keV by
extremely heavy line-of-sight absorption and the observed X-ray spectrum is
dominated by multi-temperature thermal emission associated with the nuclear
starburst and the X-ray plume. Nevertheless the signature of the AGN is present
in the form of a neutral Compton reflection component and a 6.4 keV fluorescent
iron Ka line. We conjecture that the site of the continuum reprocessing is the
far wall of a highly inclined molecular torus, a geometry which is consistent
with the presence of H2O megamaser emission in this source. The soft spectrum
(~0.6 keV) and limb-brightened appearance of the X-ray plume suggest an
interpretation in terms of a mass-loaded superwind emanating from the nuclear
starburst.

Astrophysics