A broad-band X-ray view of NGC 4945

We present the results of a BeppoSAX observation of the nearby spiral galax y NGC 4945 in the 0.1-200 keV energy band. The nuclear X-ray emission emerg es above similar or equal to 7 keV, through an absorber with column density N-H similar to a few 10(24) cm(-2) Its remarkable variability (doubling/ha lving timescale similar to 10(4) s) is not associated with any appreciable spectral changes, ruling out variations of the interposed absorber or chang es in the primary continuum shape. The intense iron K-alpha, fluorescent em ission line is likely to be produced by the same nuclear absorbing matte. O ur estimate of the intrinsic nuclear power suggests that the active nucleus dominates the bolometric energy output ofNGC 4945, if its nucleus has a ty pical quasar L-X/L-bol ratio. This supports the idea that X-rays are the be st energy band to search for absorbed AGN. The 0.1-5 keV emission is extend ed along the plane of the galaxy, and most likely due to a population of un resolved binaries, as believed to happen in several early-type galaxies. Al ternatively, hot gas associated with a starburst-driven superwind outflow c ould substantially contribute to the extended emission above 1 keV.