THE DUST GAS CORRELATION AT HIGH GALACTIC LATITUDE/

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 me asured by the Leiden/Dwingeloo survey of HI in our Galaxy. A tight cor relation is observed at high [b] at wavelengths ranging from 100 mu m to 1 mm. The dust emission spectrum derived from the correlation is fi t well by a single Planck curve characterized by T = 17.5 K and an emi ssivity proportional to nu(2). The dust emissivity tau/N-H = 1.0 10(-2 5) (lambda/250 mu m)(-2) cm(2) is remarkably close to the value in the Draine and Lee (1984) dust model and is much smaller than values pred icted Eor porous or fractal grains. In the emission from HI gas, we ex clude tile presence of a very cold dust component with comparable emis sivity, unless its temperature is significantly smaller than 7 K. We a lso discuss the contribution from Galactic molecular and ionized gas t o the global IR emission.