High resolution spectrum of the source. Upper panel: Integrated spectrum of the source extracted from the regions with S/N > 3 in the wavelength range 3.27–3.29 μm encompassing the [O III]λ5007 Å emission. The extraction region is shown as the red contour in the inset panel. Bottom panels: Zoom-in on the integrated spectrum (black) and our best fit (red). The narrow and broad components are shown as the green and blue dashed lines, respectively. The Hβ and [O III] complex is shown in the left panel, and the Hα, [N II], and [S II]λλ 6717,6731 complex is shown in the right panel. The gray shaded areas mark the uncertainties on the data.