Hβ–[O III]λλ4959,5007 spectral region in the SDSS (top panel), the X-shooter spectrum (middle panel), and the MUSE (bottom panel) spectra of PMN J0948+0022. Colors: continuum magenta – the final fit; dashed blue – the broad components of Hβ; dotted red – the narrow components of Hβ and [O III]λλ4959,5007; dotted-dashed yellow – the [O III]λλ4959,5007 blue wings, interpreted as outflows; and green – the residuals, calculated as the difference between the original data and the best-fitting model. For SDSS, the [O III]λ5007 fit is tentative; here, we applied the same model as in the other two cases, keeping in mind that we are dealing with a non-detected line.