A BRIEF HISTORY OF THE CALTECH SUBMILLILMETER OBSERVATORY
Walter R. Steiger
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"The submillimeter portion of the spectrum yields the best probes of the
physical and chemical conditions in molecular clouds, and may finally permit us
to observe how an interstellar cloud actually collapses to form a protostar."
INTRODUCTION
he development of infrared astronomy was a new and active discipline in the mid-1960s. The development of infrared detectors was the key to progress in this field. One of the active centers of this work was at Caltech where Dr. Gerry Neugebauer was a leader of the program. Neugebauer had joined with Dr. Robert Leighton to develop a small telescope to make the now famous 2 micron survey of the sky. After that was finished, Leighton turned his attention to devising methods for making larger (~ 10m) telescopes for millimeter and submillimeter wavelengths. This new field was only slowly developing, due to the lack of established detectors and the strong water vapor and oxygen absorption by the Earth's atmosphere. Nevertheless, it was a field of great interest, holding the key to star formation and the physics and the chemistry of the interstellar medium (ISM). The first three telescopes developed by Leighton, assisted by Dave Vail and Walt Schaal, were destined for the Owens Valley Radio Observatory (OVRO) where they formed an interferometer array working in the millimeter range of the spectrum. Shorter wavelengths were not accessible at this site due to the strong absorption by water vapor in the Earth's atmosphere. To gain access to the submillimeter region one must find a site that is well above a large percentage of the water vapor in the atmosphere. Early on it was recognized that Mauna Kea in Hawaii, at almost 14,000 feet elevation, would be such a site, as would White Mountain in California. And so, a fourth 10.4-m super-dish was constructed to produce diffraction-limited images in the submillimeter range. Placing a telescope on Mauna Kea involved a number of new challenges. The telescope would require a dome, not only to house and protect the telescope but also to provide space for the control room, laboratories, and other amenities required at a remote site. As for the construction of the telescope and dome, it was decided that, as it was a totally novel design, it would be optimal to build everything right on the Caltech campus in Pasadena in such a way that it could be dismantled and shipped to Hawaii for reassembly. Designing the dome began around 1981 and construction began in 1985. By 1987 the installation was basically complete, although the formal dedication took place on November 22, 1986. First light, with an image of M82, took place on March 15, 1987. The initial funding for CSO of $3.9 million came from the National Science Foundation, and the Foundation continues to support its operations. Funds were also provided by the Kresge Foundation of Troy, Michigan; Francis L. Moseley of Flintridge, California; Prince Charitable Trust of Chicago; and NASA. |
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