Extracted 1D spectra for the three quasars. In each case, the top panel shows the quasar alone and the bottom panel shows the Lyα envelope alone, after spatial deconvolution of the spectra. The vertical dotted line indicates the position of the un-absorbed Lyα emission line, at the redshift of the quasar (see Sects. 3.2 and 2.1). In all cases, the spectrum of the Lyα envelope has been smoothed using a boxcar of 8 Å.