Cosmic Background Explorer/FIRAS
CIB Monopole Spectrum
Fixsen et al. (1998) modeled the Galactic and interplanetary foreground emission in the FIRAS data to determine the spectrum of the cosmic infrared background. Three different methods were used. The CIB spectrum from each method, as shown in Figure 4 of Fixsen et al. (1998), is provided here. Fixsen et al. fit the average of the three spectra in the ν = 5-80 cm-1 frequency interval (2000-125 μm) to obtain I(ν) = (1.3 +/- 0.4) × 105(ν/ν0)0.64+/-0.12Pν(18.5 +/- 1.2 K), where ν0 = 100 cm-1 (λ0 = 100 μm), and P is the Planck function.
More details can be found in:
"The Spectrum of the Extragalactic Far-Infrared Background from the COBE FIRAS Observations"