Extrapolation of Galactic Dust Emission at 100 Microns to Cosmic Microwave Background Radiation Frequencies Using FIRAS

We present predicted full-sky maps of submillimeter and microwave emissionfrom the diffuse interstellar dust in the Galaxy. These maps are extrapolatedfrom the 100 micron emission and 100/240 micron flux ratio maps that Schlegel,Finkbeiner, & Davis (1998; SFD98) generated from IRAS and COBE/DIRBE data.Results are presented for a number of physically plausible emissivity models. We find that no power law emissivity function fits the FIRAS data from 200 -2100 GHz. In this paper we provide a formalism for a multi-component model forthe dust emission. A two-component model with a mixture of silicate andcarbon-dominated grains (motivated by Pollack et al., 1994}) provides a fit toan accuracy of about 15% to all the FIRAS data over the entire high-latitudesky. Small systematic differences are found between the atomic and molecularphases of the ISM. Our predictions for the thermal (vibrational) emission from Galactic dust at\nu < 3000 GHz are available for general use. These full-sky predictions can bemade at the DIRBE resolution of 40' or at the higher resolution of 6.1 arcminfrom the SFD98 DIRBE-corrected IRAS maps.