The Following text was taken from the ESA Science site: URL: http://isowww.estec.esa.nl/science/
SWS spectra the ultraluminous infrared galaxy Arp 220 that reveal the presence of emission lines indicating vigorous star formation.
This image has been taken from the MPG Press Release, "Europe's space telescope ISO reveals the energy source of luminous galaxies".
INFRARED PROCESSING AND ANALYSIS CENTER