Water vapor absorption lines detected toward Orion IRc2 with ISO SWS
ISO-SWS detection of 6 pure rotational water vapor absorption lines toward Orion-IRc2
Credit: ESA/ISO, SWS, C. M. Wright et al.
[High-Resolution image: Postscript]

Caption: ISO-SWS spectrum toward Orion IRc2 of 6 pure rotational water lines, overlaid on a 17 µm image of the infrared cluster. A further 13 lines are observed shortward of 40 µm, all in absorption. Toward the shock peak positions the lines occur in emission. The ordinate is in units of Jansky.

This observation has been discussed in details in the Astronomy & Astrophysics article Vol. 358, p. 689-700 (2000) entitled: "ISO-SWS observations of pure rotational H2O absorption lines toward Orion-IRc2".