HIGH-LATITUDE GALACTIC EMISSION IN THE COBE DIFFERENTIAL MICROWAVE RADIOMETER 2-YEAR SKY MAPS

We cross-correlate the COBE(6) DMR 2 year sky maps with spatial templa tes from long-wavelength radio surveys and the far-infrared COBE DIRBE maps. We place an upper limit on the spectral index of synchrotron ra diation beta(synch) < -2.9 between 408 MHz and 31.5 GHz. We obtain a s tatistically significant cross-correlation with the DIRBE maps, whose dependence on the DMR frequencies indicates a superposition of dust an d free-free emission. The high-latitude dust emission (\b\ > 30 degree s) is well fitted by a single dust component with temperature T = 18(- 7)(+3) K and emissivity epsilon proportional to (nu/nu(0))(beta) with beta = 1.9(-0.5)(+3.0). The free-free emission is spatially correlated with the dust on angular scales,larger than the 7 degrees DMR beam, w ith rms variations 5.3 +/- 1.8 mu K at 53 GHz and angular power spectr um P proportional to l(-3). If this correlation persists to smaller an gular scales, free-free emission should not be a significant contamina nt to measurements of the cosmic microwave anisotropy at degree angula r scales for frequencies above 20 GHz.