Averaged line profiles of lower-J (﹩0\leqslant J\leqslant 3﹩ for blue spectra) and higher-J (﹩4\leqslant J\leqslant 11﹩ for red spectra and ﹩J\,\gt ﹩ 11 for green spectra) CO transitions for IRAS 04239+2436. The optical depth is normalized to the absorption peak.