The infrared sky at the north celestial polar cap is displayed in this image constructed from nine fields of the Infrared Astronomical Satellite (IRAS) Sky Survey Atlas. The image is a composite of 12 micron (coded blue), 60 micron (green), and 100 micron (red) wavelengths. The stars are the warmest features in the picture, and show up as small blue dots, since they radiate brightly in the 12 micron wavelength. The yellow dots are galaxies, which shine brightest in the 60 micron and 100 micron wavelengths.
The picture is centered on the north pole and extends to +74 degrees. The field is dominated by infrared "cirrus" --- interstellar dust grains heated by the ambient stellar radiation field.
The IRAS Sky Survey Atlas (ISSA) is the latest image product to come from the reprocessing of the IRAS wavelength data. The improved calibration and destriping methods reveal low surface brightness structure not seen in other IRAS products.
INFRARED PROCESSING AND ANALYSIS CENTER