The Following text was taken from the ESA Science site: URL: http://isowww.estec.esa.nl/science/
Observations using all 25 ISOPHOT-P and -C filters giving the shape of the 3 to 240 µm Spectral Energy Distribution of NGC 6240. The squares represent the four photometric IRAS points.
Further details of these observations can be found in the Astronomy and Astrophysics letter; "Infrared spectral energy distributions of the interacting galaxies Arp 244, NGC 6240, and Arp 220".
INFRARED PROCESSING AND ANALYSIS CENTER