DEGREE-SCALE ANISOTROPY IN THE COSMIC MICROWAVE BACKGROUND - SP94 RESULTS

We present results from two observations of the cosmic microwave backg round (CMB) performed from the South Pole during the 1993-1994 austral summer. Each observation employed a 3 degrees peak-to-peak sinusoidal , single-difference chop and consisted of a 20 degrees x 1 degrees str ip on the sky. The first observation used a receiver which operates in three channels between 38 and 45 GHz (Q-band) with a FWHM beam which varies from 1 degrees to 1.degrees 15. The second observation overlapp ed the first observation and used a receiver which operates in four ch annels between 26 and 36 GHz (Ka-band) with a FWHM beam which varies f rom 1.degrees 5 to 1.degrees 7. Significant correlated structure is ob served in all channels for each observation. The spectrum of the struc ture is consistent with a CMB spectrum and is formally inconsistent wi th diffuse synchrotron and free-free emission at the 5 sigma level. Th e amplitude of the structure is inconsistent with 20 K interstellar du st; however, the data do not discriminate against flat or inverted spe ctrum point sources. The root mean square amplitude (+/- 1 sigma) of t he combined (Ka + Q) data is Delta T-rms = 41.2(-6.7)(+15.5) mu K for an average window function which has a peak value of 0.97 at l = 68 an d drops to e(-0.5) of the peak value at l = 36 and l = 106. A band pow er estimate of the CMB power spectrum, C-l, gives [C-l(l)(l + 1)/(2 pi )](B) = 1.77(-0.54)(+1.58) x 10(-10).