DIRBE Science Images
The images shown below were created from the COBE DIRBE data products . The colors generally do not map linearly into sky brightness. Use the original data products for quantitative analysis. Additional images are available in the COBE Slide Set.
Image Credit: NASA / COBE Science Team
To view the original images, click on the postage-stamp versions:
All of the Solar elongation angle = 90 deg Maps are shown with logarithmic intensity scales. The following table gives the minimum and maximum log(I) for each DIRBE photometric band.
The zodiacal and Galactic emission must be precisely modeled and subtracted in order to detect the relatively faint Cosmic Infrared Background which the DIRBE was designed to find. Secondary DIRBE objectives include studies of these astrophysical foreground components.
The following two figures were provided by Dr. Henry T. Freudenreich and are described in his paper on The Shape and Color of the Galactic Disk ( 1996, ApJ, 468, 663). The Galactic plane runs horizontally through each figure. The Galactic center lies along the 0 degree meridian and the anti-center direction appears near the left side of each map. The 90 degree meridian is labeled for scale.
Bottom: The surface brightness at 240 µm. At this wavelength, in the far-infrared, stars are invisible and we see thermal emission from dust heated by starlight. The range of surface brightness is 0 to 115 MJy/sr. This map is bright where the top map is dark because the same interstellar dust clouds that absorb background starlight at near-infrared wavelengths are warmed by this absorption to about 20 degrees Kelvin, making them sources of far-infrared emission.
Bottom: The surface brightness at 240 µm multiplied by the sine of the Galactic latitude. This procedure accentuates the relatively nearby interstellar clouds, such as the molecular clouds in Orion (lower far left), Taurus (to the right of Orion) and Ophiuchus (above Galactic center). When scaled by the sine of latitude, the map intensity ranges from 0 to 13 MJy/sr. Comparison of this map to the K-L map shows that regions containing cool dust tend to coincide with regions containing hot, small dust grains. The molecules or tiny grains seem to be a general component of the interstellar dust.