Mean (solid black) and rms (dashed red) line profiles of Hβ (left panel) and Hα (right panel). The central velocity v = 0 km s⁻¹ is indicated by a black dashed line. The Hβ and Hα rms profiles show a peak at +(220 ± 50) km s⁻¹ and +(210 ± 50) km s⁻¹, respectively, with respect to the central wavelength. The profiles are strongly asymmetric with the red wing being broader by about ∼400 km s⁻¹. The FWHM amounts to (2180 ± 50) km s⁻¹ and (2060 ± 50) km s⁻¹ for Hβ and Hα, respectively.