CO spectra toward IRAS 15103−5754. From top to bottom: CO(J = 10 → 9) and CO(J = 5 → 4) obtained with Herschel (this paper), and 13CO(J = 1 → 0) spectrum from the rms survey (Urquhart et al. 2007b). The two Herschel spectra have been multiplied by 10 and shifted vertically, to improve their visualization