Upper panel: mosaicked count-rate images (MOS-equivalent counts per second per bin) of SN 1006 in the 2−4.5 keV band. The bin size is 4′′ and the image is adaptively smoothed to a signal-to-noise ratio ten. The regions selected for the spectral analysis of the rim are superimposed (four in the upper panel and four in the lower panel for clarity). North is up and East is to the left. The two dashed lines indicate the symmetry axis of the remnant, marking the center of the synchrotron limbs (northeast and southwest) and of thermal limbs (northwest and southeast). Lower panel: same as upper panel in the 0.5−0.8 keV energy band.