Animated DIRBE Weekly 25 Micron Residual Maps

The Figure below shows the 25 micron weekly residual maps from DIRBE as an animated GIF file. At this wavelength, the zodiacal emission dominates the sky. The thin linear feature wiggling through the Figure is the Galactic plane. Note the the Galactic emission has been subtracted, but large gradient near the plane give the feature.

The top of the figure is 61 degrees from the Sun, while the bottom is 131 degrees from the Sun. The NEP is the middle of the right and left sides, while the SEP is the middle of the figure. The trailing edge [ecliptic latitude = 0, longitude = 90o more than the Sun's longitude] is halfway between the left edge and the middle of the Figure.

The model whose residuals are shown here is an offset, tilted, widened Good model. The range of colors is +/- 1 MJy/sr. The median average intensity at 25 microns is 32 MJy/sr.

Note that the trailing edge is systematically brighter than the leading edge. This residual is caused by the clump behind the Earth in the ring of interplanetary dust grains trapped at 1 au from the Sun by resonant interactions with the Earth. See Dermott et al., 1994, Nature, 369, 719; and Reach et al., 1995, Nature, 374, 521.

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© 1998-2005 Edward L. Wright. Last modified 12 Dec 2005