Cross-spectral signal for ℓ = 200, Δℓ = 2, and n = 0. (a), (b) Observed cross-spectrum corresponding to m⁺ and m⁻. (c), (d) Derotated cross-spectrum corresponding to m⁺ and m⁻. (e), (f) ﹩{D}_{n}^{{\ell },{\rm{\Delta }}{\ell },\pm }﹩. The baseline is indicated by the dashed blue line. The blue dots represent observations from the five 72-day time series, and the red curve corresponds to the expectation value of the cross-spectrum.