Left: spectrum measured from the residual in Fig. 6 in the region | l |  < 35°, − 35° < b <  − 10°. The haze spectrum is very nearly a power law with spectral index β_H =  − 2.56, while the total synchrotron emission in the region has a spectral index of β_S =  − 3.1 (see Sect. 4.3), significantly softer than the haze emission. This spectrum should be free from biases caused by template uncertainties. Middle and right: scatter plots (shown in contours) for both the haze (dotted) and total synchrotron (solid) emission using WMAP 23–33 GHz and Planck 30 GHz.