[O III] map (top-right) and integrated spectra of the dual AGN system and a faint clump associated with COS1656. The [O III] map is obtained by integrating the [O III] emission over a velocity range from −200 to +200 km s⁻¹, in order to highlight the primary (AGN-A) and secondary (AGN-B) nuclei; the contours trace the emission at v ∈ [ − 800, −600] associated with a clump close to AGN-B. The remaining panels show the integrated spectra of the primary (top-left) and secondary (bottom-left) AGNs, as well as of the clump (bottom-right), extracted from the circular regions labelled in the map. The legend display the individual Gaussian components and best-fit curves shown in the spectra; best-fit total profiles are represented in red for AGN-A, in blue for AGN-B, and in magenta for the clump. Residuals, defined as the difference between the observed data and the best-fit model, are displayed at the bottom of each panel; average ±3σ uncertainties on the data are also reported with grey shaded regions. The vertical green and blue shaded areas at ∼5007 Å mark the channels used to generate the [O III] map and contours in the top-right panel, respectively.