Spectral index maps of the inner region of the three clusters in the A3528 cluster complex. From left to right: A3528N, A3528S, and A3532. Top rows: High resolution (Θ ∼ 7″); bottom rows: Low resolution (Θ ∼ 19″, i.e. taper=15″). The corresponding uncertainty error maps are shown in Fig. C.1 Radio contours are drawn at 3σ_rms × [1, 2, 4, 8, 16, 32] of the uGMRT Band 4 observations at the same resolution (not primary beam corrected; see Table 3 for the noise level).