Wavelength region between 4800 and 5100 Å of the western blob ejecta (blue data) and the eastern blob (orange data) detected in the MUSE-NFM dataset. The dashed gray lines mark the rest-frame wavelength for the Hβ and the [O III] 4959/5007 lines. While Hβ is mainly detected at a zero velocity offset, suggesting it mainly comes from the gas surrounding the progenitor WD, [O III] lines show a radial velocity offset originating from the ejecta of the 2011 outburst.