The Chandra Carina Complex Project: Deciphering the Enigma of Carina's   Diffuse X-ray Emission
  We present a 1.42 square degree mosaic of diffuse X-ray emission in the Great Nebula in Carina from the Chandra X-ray Observatory Advanced CCD Imaging Spectrometer camera. After removing >14,000 X-ray point sources from the field, we smooth the remaining unresolved emission, tessellate it into segments of similar apparent surface brightness, and perform X-ray spectral fitting on those tessellates to infer the intrinsic properties of the X-ray-emitting plasma. By modeling faint resolved point sources, we estimate the contribution to the extended X-ray emission from unresolved point sources and show that the vast majority of Carina's unresolved X-ray emission is truly diffuse. Line-like correlated residuals in the X-ray spectral fits suggest that substantial X-ray emission is generated by charge exchange at the interfaces between Carina's hot, rarefied plasma and its many cold neutral pillars, ridges, and clumps. 
Leisa K. Townsley, Patrick S. Broos, You-Hua Chu, Marc Gagn\'e, Gordon   P. Garmire, Robert A. Gruendl, Kenji Hamaguchi, Mor...
astro-ph.SR astro-ph.HE