Av extinction map (Dobashi et al. 2013). The red isocontours are A_Ks of 0.65, 1.55, 2.44, and 3.34 mag, respectively. The blue, green, and cyan contours underline extinction features at 2, 5, and 9.5 kpc respectively, delineated from Marshall et al. (2006) extinction data cubes. The Hα mosaic contour is drawn in black and the Hα emission of the main H II regions is displayed (from the larger-scale SuperCOSMOS Hα Survey (SHS) image) as yellow isocontours.