Early Results from SPARO: Instrument Characterization and Polarimetry of NGC 6334

The Submillimeter Polarimeter for Antarctic Remote Observations (SPARO) employs two nine‐element arrays of 3He‐cooled bolometers to measure linear polarization at λ = 450 μm. It is operated at the focal plane of the Viper telescope, located at the Amundsen‐Scott South Pole Station. SPARO obtains better sensitivity to degree‐scale polarized submillimeter emission than can be currently achieved with any other experiment. We describe the design of SPARO's optics, detectors, and electronics. We also review the design of the SPARO cryostat, which has already been discussed in a previous paper. We discuss the performance of SPARO and Viper during observations at the South Pole in 2000, and we present polarimetric observations of NGC 6334 made with SPARO. Finally, we compare these observations with submillimeter polarimetric observations of the same source made at the Caltech Submillimeter Observatory and the James Clerk Maxwell Telescope, and we discuss the implications of these three data sets for the magnetic field in NGC 6334.