Coverage of CO observations. For each HERACLES dwarf galaxy we show the coverage of our CO data (gray dashed line), the H i surface density (gray scale) at linear scale between 0 and 40  M _☉ pc ⁻², the 24 μm intensity (red contour) at 0.2 MJy sr ⁻¹, the FUV intensity (blue contour) at 0.01 MJy sr ⁻¹, and a galactocentric radius R = R ₂₅ (white contour). We determine the CO intensity at each sampling point (dot) and stack the data for the "entire" galaxy (black contour) and for IR-bright regions (red contour); see the text for definition of stacking regions.