CSO/JCMT Interferometry

Caltech Submillimeter Observatory Office, 111 Nowelo St., Hilo, Hawai'i 96720 Voice: (808) 935-1909 Fax: (808) 961-6273

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The CSO can be joined with its neighbor, the James Clerk Maxwell Telescope (JCMT), to produce a single baseline interferometer yielding a finest angular reolution corresponding to an antenna the size of the spacing between the two telescopes. This is the first astronomical interferometer at submillimeter wavelengths, and opens up new ppossibilities for studying objects at high angular resolution.

The baseline is 157.91 meters east-west and 1.93 meters toward the celestial equator. This yields a best angular resolution of about 1.1'' at 345 GHz. Because it is only one baseline, imaging is very limited, however, source sizes can be determined quite well. The interferometer can use the 230 GHz band and 345 GHz band receivers. The correlator has 800 channels which can be split into up to 8 subbands of 125 MHz bandwidth.

The sensitivity of the interferometer is dependent on the correlator configuration, telescope efficiencies, and system temperatures. Typical values are 1 Jy in 1 second in continuum mode and 20 Jy in 1 second in spectral line mode with a 1 km/s channel width. Atmospheric fluctuations limit integration times to about 100 seconds.

For more information about using the CSO/JCMT int/erferometer, contact John Carlstrom (jc@astro.caltech.edu) or Richard Hills (richard@mrao.cam.ac.uk).