INFRARED SPACE OBSERVATORY (ISO) SPOTS WATER AMONG THE STARS
Click on the image to retrieve a larger one.
The composite picture shows fingerprints of water vapour (labelled H2O)
in widely differing infrared wavebands, as registered by two instruments
of ESA's space telescope ISO when it was trained on the elderly star W Hydrae.
In a high-resolution spectrum from the Short Wavelength Spectrometer (SWS) the
main water feature is the strong emission at wavelengths around 38 microns.
The Long Wavelength Spectrometer (LWS) picked up a large number of strong water-vapour emissions at
wavelengths from 122 to 183 microns.
The two spectra are overlaid on an image taken with the camera ISOCAM at
wavelengths of 7 and 15 microns. It shows the dark star-forming cloud
called Rho Ophiuchi, partially opened to view by the penetrating power
of ISO's infrared "eyes".
ISO's spectrometers have detected water in the vicinity of newly forming
stars as well as near dying stars. Indeed ISO is finding water
throughout the Galaxy -- in our own backyard in comets like Hale-Bopp
and on the outer planets, and in far-flung clouds towards the centre of
the Milky Way.
- Composite: ESA/ISO and the ISOCAM, LWS and SWS Consortia.
- Rho Ophiuchi image: ESA/ISO, CEA Saclay, ISOCAM and Abergel et al.
- W Hydrae, LWS Spectrum: ESA/ISO, LWS and Barlow et al.
- SWS Spectrum: ESA/ISO, SWS and Neufeld et al.