SIMBAD references

We have correlated the far-infrared emission from dust as measured by the DIRBE and FIRAS experiments with the 21-cm emission from gas as measured by the Leiden/Dwingeloo survey of HI in our Galaxy. A tight correlation is observed at high |b| at wavelengths ranging from 100µm to 1mm. The dust emission spectrum derived from the correlation is fit well by a single Planck curve characterized by T=17.5K and an emissivity proportional to ν². The dust emissivity τ/N_H=1.0x10^–25 (λ/250µm)^–2cm² is remarkably close to the value in the Draine and Lee (1984) dust model and is much smaller than values predicted for porous or fractal grains. In the emission from HI gas, we exclude the presence of a very cold dust component with comparable emissivity, unless its temperature is significantly smaller than 7K. We also discuss the contribution from Galactic molecular and ionized gas to the global IR emission.