A spatially resolved spectral study of the North Polar Spur

GT The bright Xray feature North Polar Spur (NPS) is the result of a supernovaremnant shock interacting with the inner walls of the giant supershell aroundthe ScoCen OB association. It has been shown that the shock from a 10^{51} ergexplosion within the Loop I superbubble can heat the dense shell to temperaturesof 34 10^6 K, giving rise to the observed Xray emission. The shock runninginto the density gradient in the wall is rapidly decelerated, and strong cooling can lead to nonequilibrium effects like overionization.. Using EPIC pn, we canstudy emission line ratios in the 0.3 2.0 keV range and thus determine theplasma state. Three adjacent 20 ksec observations will cover the steepestgradient in Xray brightness. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]