PRELIMINARY SEPARATION OF GALACTIC AND COSMIC MICROWAVE EMISSION FOR THE COBE DIFFERENTIAL MICROWAVE RADIOMETER

The COBE Differential Microwave Radiometer (DMR) anisotropy experiment is sufficiently sensitive and free from systematic errors that our knowledge of Galactic emission is a limiting factor in interpreting the measurements of the 1 yr DMR maps. In this paper we construct preliminary models of microwave emiSSion from our Galaxy based on COBE and other data for the purpose of distinguishing cosmic and Galactic signals. DMR maps, with the modeled Galactic emission removed, are fitted for a quadrupole distribution. Our best estimate of the cosmic quadrupole is found to be Q(rms) = 13 +/- 4-mu-K, (DELTA-T/T)Q = (4.8 +/- 1.5) x 10(-6). Autocorrelation functions for individual Galactic components are presented. When Galactic emission is removed from the DMR data, the residual fluctuations are virtually unaffected, and therefore they are not dominated by any known Galactic emission component.