Velocity dispersion and FUV emission. Visual inspection of spatial correlation of velocity dispersion (σ_eff the colorbar represents units of km s⁻¹) and FUV emission as an indicator of star formation (in units of mJy arcsec⁻²). The FUV emission is the same GALEX FUV map as shown by Bigiel et al. (2010a). We defined 6 individual sub-regions in the ring, southern area, southern and northern arm, based on where we see either stronger FUV emission or enhanced velocity dispersion. See Sect. 4.1 for the discussion on the different regions.