XMM-Newton detection of hot gas in the Eskimo Nebula:: Shocked stellar wind or collimated outflows?

The Eskimo Nebula (NGC2392) is a double-shell planetary nebula (PN) known for the exceptionally large expansion velocity of its inner shell, similar to90 km s(-1), and the existence of a fast bipolar outflow with a line-of-sight expansion velocity approaching 200 km s(-1). We have obtained XMM-Newton observations of the Eskimo and detected diffuse X-ray emission within its inner shell. The X-ray spectra suggest thin plasma emission with a temperature of similar to2x10(6) K and an X-ray luminosity of L-X=(2.6+/-1.0)x10(31)(d/1150 pc)(2) erg s(-1), where d is the distance in parsecs. The diffuse X-ray emission shows noticeably different spatial distributions between the 0.2-0.65 keV and 0.65-2.0 keV bands. High-resolution X-ray images of the Eskimo are needed to determine whether its diffuse X-ray emission originates from shocked fast wind or bipolar outflows.