Where in the Milky Way is the North Polar Spur

The North Polar Spur (NPS) is a region of strong diffuse Xray emission that isgenerally thought to be the edge of the Loop I superbubble, at a distance ofvirgul150pc. However, it may also be the limb of a supershell at the Galactic center.The implications for the plasma, energy, and dynamics involved are extreme. Wewill determine the location of the NPS using a series of overlappingobservations of the southern terminus of the NPS. Comparison with the Galacticdistribution of Xray absorbing material will allow us to constrain the distanceto the Xray emission. This proposal requests the reobservation of threepointings from our accepted AO13 large project which were contaminated by softprotons beyond usage. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]