Cosmic Microwave Background Anisotropy Measurements on Arcminute Scales
Session 62 -- Large Scale Structures
Display presentation, Thursday, 2, 1994, 10:00-11:30

## [62.11] Cosmic Microwave Background Anisotropy Measurements on Arcminute Scales

The results of two experiments to measure anisotropy in the cosmic microwave background on arcminute scales are presented. These observations were conducted at the Owens Valley Radio Observatory using the 40m telescope (18.5 GHz, $2'$ FWHM, $7.\mkern-4mu^\prime15$ chop) and the new 5.5m telescope (32 GHz, $7.\mkern-4mu^\prime3$, $22.\mkern-4mu^\prime16$ chop). New 40m data on the NCP40m (Readhead et. al. 1989, NCP89) and RING40m (Myers {\it et. al.} 1993, RING93) surveys are presented, the former reaching a noise level of $20\,\mu\mbox{K}$ in each of 12 independent fields, and the latter reaching the sensitivity of RING93 in only one month of data. Results from the new RING5m program using the 5.5m telescope with error bars of $24\,\mu\mbox{K}$ in each of 36 interlocked fields are also presented. There are excess fluctuations over noise detected in both experiments --- approximately $66\,\mu\mbox{K}$ for the NCP40m and $86\,\mu\mbox{K}$ for the RING5m --- much of which can be attributed to contamination by point sources (radio galaxies and quasars). The 7 fields of the NCP40m that were measured previously in the NCP89 20 GHz data are roughly consistent with the new data taken at the slightly lower frequency of 18.5 GHz. The contamination in the 5.5m data is investigated using results of a 40m survey of the RING5m fields using drift scanning. A new 13-16 GHz system is currently being installed on the 40m telescope to observe the RING5m fields to search for galactic (and extragalactic) foreground contamination of the microwave background data. The first results of this follow-up, and a new VLA survey of the NCP40m fields, will be reported if available by the time of the meeting.