cosmic infrared background (CIB)
Spitzer Space Telescope image of a small patch of sky in the constellation Draco. Top is the original infrared image, showing numerous foreground stars and galaxies; bottom is a processed image with all these foreground objects removed, revealing the cosmic infrared background. Credit: NASA/JPL-Caltech/J. Kashlinsky (GSFC).
The cosmic infrared background (CIB) is the total of the redshifted and reprocessed radiation from the era of galaxy formation. The intensity and spectrum of the CIB provides information about the history of star formation, the history of galaxy formation, and the presence or absence of dust in early galaxies.
Measurements of the CIB by the 2MASS telescope, published in 2002, confirmed earlier estimates by COBE (Cosmic Background Explorer) that the CIB is two to three times brighter than expected based on extrapolations of observed galaxies. The brightness indicates that there was an incredible burst of star formation during the Universe's youth. It also supports the idea that a great deal of dark matter was present, pulling gas together shortly after the Universe's birth, and enabling the first stars and galaxies to form.
The CIB is one of several components of the cosmic background radiation.