Top: SED of the primary (more massive) SMBH in red. Each of the 100 emitting radii are shown in gray. Middle: Same plot, but for the secondary (lighter) SMBH. Bottom: Combined SED of the two SMBHs in a binary system based on the model proposed by Yan et al. (2015), with M_*, p = 1.5 × 10⁸ M_⊙, r_int, p = 3.38 × 10⁻³ pc and r_out, p = 6.80 × 10⁻³ pc for the primary SMBH, and M_*, s = 4.5 × 10⁶ M_⊙, r_int, s = 1.29 × 10⁻⁶ pc and r_out, s = 4.51 × 10⁻⁵ pc for the secondary SMBH.