ON THE RMS ANISOTROPY AT 7-DEGREES AND 10-DEGREES OBSERVED IN THE COBE(1)-DMR 2-YEAR SKY MAPS

The frequency-independent rms temperature fluctuations determined from the COBE-DMR two-year sky maps are used to infer the parameter Q(rms- PS), which characterizes the normalization of power-law models of prim ordial cosmological temperature anisotropy, for a forced fit to a scal e-invariant Harrison-Zel'dovich (n = 1) spectral model. Using a joint analysis of the 7 degrees and 10 degrees ''cross''-rms derived from bo th the 53 and 90 GHz sky maps, we find Q(rms-PS) = 17.0-(+2.5)(2.1) mu K when the low quadrupole is included, and Q(rms-PS) = 19.4(+2.1)(+2. 3) mu K excluding the quadrupole. These results are consistent with th e n = 1 fits from more sensitive methods. The effect of the low quadru pole derived from the COBE-DMR data on the inferred Q(rms-PS) normaliz ation is investigated. A bias to lower Q(rms-PS) is found when the qua drupole is included. The higher normalization for a forced n = 1 fit i s then favored by the cross-rms technique.