Continuum spectral index distribution in the inner ≲1.6 pc. Top: between 100 and 250 GHz (inner 40′′) tapered to a resolution of 1.5′′ with contours of [–0.75, –0.5, –0.375, –0.25, –0.125, 0, 0.25, 0.5, 1, 1.5]. Bottom: between 250 and 340 GHz (inner 20′′) tapered to a resolution of 0.65′′ with contours of [–2, –1, –0.5, 0, 0.5, 1, 2]. Maps on the uncertainties can be found in Fig. A.10.