Mapping the cosmic microwave background anisotropy: Combined analysis of QMAP flights

We present results from the QMAP balloon experiment, which maps the cosmic microwave background (CMB) and probes its angular power spectrum on degree scales. In two separate flights, data were taken in six channels at two frequency bands between 26 and 46 GHz. We describe our method for mapmaking (removal of 1/f-noise and scan-synchronous offsets) and power spectrum estimation as well as the results of a joint analysis of the data from both flights. This produces a 527 deg(2) map of the CMB around the north celestial pole, allowing a wide variety of systematic cross-checks. The frequency dependence of the fluctuations is consistent with CMB and inconsistent with Galactic foreground emission. The anisotropy is measured in three multipole bands from l similar to 40 to l similar to 200, and the angular power spectrum shows a distinct rise that is consistent with the Saskatoon results.