Robert F. Loewenstein

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To investigate the low-atmosphere turbulence at the South Pole, we have measured, using a SODAR, the temperature fluctuation constant (C2 T ) during winter, as a function of altitude up to 890 m. We found that the turbulence was on average concentrated inside a boundary layer sitting below 270 m. While at the peak of winter the turbulence was stable and(More)
The statistics and dynamics of the atmospheric seeing at the South Pole have been studied over a period of 101 days in winter. These measurements have been made with the first fully autonomous differential image motion monitor, the A-DIMM. The analysis shows an average seeing of 1.9′′ with a standard deviation of 0.6′′. The extensive set of data has allowed(More)
We have observed the linear polarization of 450 mm continuum emission from the Galactic center, using a new polarimetric detector system that is operated on a 2 m telescope at the South Pole. The resulting polarization map extends ∼170 pc along the Galactic plane and ∼30 pc in Galactic latitude, and thus covers a significant fraction of the central(More)
The Submillimeter Polarimeter for Antarctic Remote Observations (SPARO) employs two nineelement arrays of He-cooled bolometers to measure linear polarization at mm. It is operated at the focal l p 450 plane of the Viper telescope, located at the Amundsen-Scott South Pole Station. SPARO obtains better sensitivity to degree-scale polarized submillimeter(More)
  • Eric Bell, David Barnaby, +5 authors Bernard J. Rauscher
  • 2008
We have performed deep imaging of a diverse sample of 26 low surface brightness galaxies (LSBGs) in the optical and the near-infrared. Using stellar population synthesis models, we find that it is possible to place constraints on the ratio of young to old stars (which we parameterise in terms of the average age of the galaxy), as well as the metallicity of(More)
We present results from the Austral Winter 2003 observing campaign of SPARO, a 450 µm polarimeter used with a two-meter telescope at South Pole. We mapped large-scale magnetic fields in four Giant Molecular Clouds (GMCs) in the Galactic disk: NGC 6334, the Carina Nebula, G333.6-0.2 and G331.5-0.1. We find a statistically significant correlation of the(More)
We present first results of Hertz/VPM, the first submillimeter polarimeter employing the dual Variable-delay Polarization Modulator (dual-VPM). This device differs from previously used polarization modulators in that it operates in translation, rather than mechanical rotation. We discuss the basic theory behind this device and its potential advantages over(More)
A new echelle spectrograph was commissioned in 1999 for the ARC 3.5 meter telescope. The key features of the instrument are that it has a resolution of 9 km/sec, limited by the pixel size of the CCD; has no moving parts behind the slit during observation; provides complete spectral coverage from 3200A to 10000A, limited by the prism cross disperser material(More)
We present new submillimeter polarimetric observations of the Galactic center region, made using the SPARO polarimeter that operates at the South Pole. Compared with previous submillimeter polarimetry of this region, our measurements cover much more sky area, and they imply that the molecular gas in the central few hundred pc is threaded by a large scale(More)