Comparison between X-ray absorption and Hα emission. The left panel displays a smoothed map of our measured N_H values toward Vela, with contours at the level of N_H = 1.7, 3.0, 6.0, 10.0 × 10²⁰ cm⁻². The same contours are overlaid on a map of the surface brightness of Hα emission in the region in the right panel. Both panels employ a linear color scale, and have been masked as in Fig. 5.