The Following text was taken from the ESA Science site: URL: http://isowww.estec.esa.nl/science/
Normalised SWS spectra of NGC 7538 IRS9, GL4176, GL2136 and GL2591, shifted by 0.0, -0.2, -0.4 and -0.6 respectively. A model H2O spectrum is shown for comparison
This spectrum was presented in letter "Infrared absorption of H2O toward massive young stars", van Dishoeck, E.F. et al., that was published in the ISO dedicated issue of Astronomy and Astrophysics Letters.
INFRARED PROCESSING AND ANALYSIS CENTER