a) Visible spectra of the four images of QSO2237+0305 acquired on October 11 2005. b) Mean near-infrared spectra obtained by combining all the valid spectra secured in October 2005. A typical SINFONI image of the QSO2237+0305 system, obtained by integrating the infrared flux over wavelength, is illustrated in the right panel. c)–f) Zoom on the CIV, CIII], MgII and Hα line profiles, plotted vs. the Doppler shift relative to the line laboratory wavelength redshifted to the quasar rest-frame. The spectra were rescaled so that their continua superimpose in the neighborhood of the lines. Vertical dotted lines indicate the positions of the lines in the quasar rest-frame. Hatched surfaces cover the wavelength ranges that suffer from important atmospheric absorption. The spectra are smoothed in wavelength using a 3-pixel wide median filter.