Evolution of the Paα emission line (upper subplots) and corresponding differential phase (Δϕ, lower subplots) for the CB-SMBH system as a function of the wavelength and radial velocity. The clouds’ orbital eccentricities are drawn from Rayleigh distribution. Varying parameters are listed in sub-captions and legends, and 𝒞 stands for coplanar orbits. (a) 𝒞, Ω_k = 100° , ω₁ = 110° ,ω₂ = 290° ,i_c = 𝒰(−5° ,5° ), Ω_c1 = 200° , Ω_c2 = 10° , ω_c1 = 150° ,ω_c2 = 330° ,e_c1 = e_c2 = rndℛ(1), (b) 𝒞, Ω_k = 100°, k = 1, 2, ω₁ = 110° ,ω₂ = 290° ,𝒞, Ω_c1 = 200° ,Ω_c2 = 10°, ω_c1 = 150° ,ω_c2 = 330°, e_c1 = e_c2 = rndℛ(1), (c) 𝒞, Ω_k = 100°, k = 1, 2, ω₁ = 110°, ω₂ = 290° ,i_c1 = 𝒞, i_c2 = 𝒰(−5° ,5° ), Ω_c1 = 200° ,Ω_c2 = 10° , ω_c1 = 150°, ω_c2 = 330° ,e_c1 = rndℛ(1), e_c2 = 0.5, (d) 𝒞, Ω_k = 100°, k = 1, 2, ω₁ = 110° ,ω₂ = 290°, i_c1 = 𝒞, i_c2 = 𝒰(−5° ,5° ), Ω_c1 = 200° , Ω_c2 = 10°, ω_c1 = 150° ,ω_c2 = 330°, e_c1 = e_c2 = rndℛ(1), (e) 𝒞, Ω_k = 100°, k = 1, 2, ω₁ = 110° ,ω₂ = 290°, i_c1 = i_c2 = 𝒰(−5° ,5° ), Ω_c1 = 200° ,Ω_c2 = 10°, ω_c1 = 150° ,ω_c2 = 330°, e_c1 = 0.5, e_c2 = rndℛ(1).