2007/04/20 by T. R. Hunter, Antony Schinckel, A. E. T. Schinckel +20 · 1 citation
Engineering · Physics and Astronomy · #Antenna Design and Optimization #Microwave Engineering and Waveguides #Radio Astronomy Observations and Technology #astro-ph
paper · pdf · doi:10.48550/arxiv.0704.2641
13 pages, 11 figures, originally presented as a poster at the 201st AAS meeting held in Seattle, WA in January 2003
arxiv created 2007/04/20 · arxiv updated 2009/12/01
Phase closure at 682 GHz and 691 GHz was first achieved using three antennas of the Submillimeter Array (SMA) interferometer located on Mauna Kea, Hawaii. Initially, phase closure was demonstrated at 682.5 GHz on Sept. 19, 2002 using an artificial ground-based "beacon" signal. Subsequently, astronomical detections of both Saturn and Uranus were made at the frequency of the CO(6-5) transition (691.473 GHz) on all three baselines on Sept. 22, 2002. While the larger planets such as Saturn are heavily resolved even on these short baselines (25.2m, 25.2m and 16.4m), phase closure was achieved on Uranus and Callisto. This was the first successful experiment to obtain phase closure in this frequency band. The CO(6-5) line was also detected towards Orion BN/KL and other Galactic sources, as was the vibrationally-excited 658 GHz water maser line toward evolved stars. We present these historic detections, as well as the first arcsecond-scale images obtained in this frequency band.