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CfA Press Release
 

SMITHSONIAN BREAKS GROUND FOR UNIQUE ASTRONOMICALINSTRUMENT ON MAUNA KE'A

MAUNA KE'A, Hawai'i--Smithsonian Institution Secretary I.Michael Heyman will officiate at the groundbreaking todayfor an unusual array of six antennas that will serve as asingle large telescope sensitive to submillimeterradiation, a region of the spectrum called "the lastfrontier of ground-based observational astronomy."

Some 100 guests, including state officials, astronomersfrom around the world, and representatives of theSmithsonian and the University of Hawai'i will join Heymanjust below the summit of Mauna Ke'a, on the big island ofHawai'i, for a traditional blessing of the site byMonsignor Charles A. Kekumano and chanter Kepa Maly. Thesite is within the Mauna Ke'a Science Reserve administeredby the Institute for Astronomy of the University ofHawai'i.

The instrument planned by the Smithsonian will be an arrayof six, movable, 6-meter-diameter antennas, each sensitiveto submillimeter radiation and capable of being positionedin different configurations. At their widest separation,the individual antennas, which are operated in concert,act like a single, giant antenna about 460 meters (1500feet) in diameter.

The submillimeter region of the electromagnetic spectrumlies in a band between radio and infrared radiation. "Ithas remained largely unexplored because the technology toproduce the precisely figured antennas and sensitivereceivers needed for detection of submillimeter radiationdid not exist until recently," notes Irwin Shapiro,director of the Smithsonian Astrophysical Observatory,which will construct and operate the new instrument.

"The Smithsonian's Submillimeter Array will be unique inits ability to observe at high angular resolution manymysterious astronomical objects and phenomena verydifficult or impossible to study with ordinary opticaltelescopes," Shapiro adds.

Because submillimeter radiation emitted by molecules canpenetrate otherwise light-blocking clouds of dust and gas,the array will be particularly well-suited for studyingstar-birth regions in the Milky Way, mapping distantgalaxies, probing the cores of powerful quasars, andobserving "cool" material, such as comets, in the SolarSystem.

By combining and integrating the submillimeter radiationreceived by each of the six antennas, the array will becapable of producing images of astronomical objects with aresolution some 10 times better than any single-dishsubmillimeter telescope.

A system of widely separated concrete pads, linked byunpaved service roads, will allow reconfiguration of theantennas by a mobile transporter. Equipped withoversized, low-pressure tires and designed to lift andcarry loads up to 30 tons, the transporter will travel atspeeds less than 8 kilometers per hour (5 mph). Reconfiguration of the pads will occur only every 2 to 3months and will take no more than a few days.

"We are extremely pleased the Smithsonian has chosen MaunaKe'a as the site for its instrument," says Donald Hall,director of the University of Hawai'i's Institute forAstronomy.

"The mountain obviously offers the high, dry atmospherenecessary for submillimeter observations," he adds. "TheSmithsonian's array also promises to complement and extendthe capabilities of the existing James Clerk Maxwell andCaltech submillimeter telescopes on Mauna Ke'a,particularly in the research areas of star formation andstudies of distant galaxies."

Preparation of the site and construction of the instrumentpads and their central control building should begin laterthis month.

The total capital cost of the submillimeter array isestimated to be about $40 million provided by directfederal appropriations to the Smithsonian Institution. Once operational in late 1997 or 1998, the array will havea Hilo-based staff of approximately 25. However, theinstrument will be available to qualified investigatorsfrom around the world; scores of astronomers from theSmithsonian and other institutions are expected to use iteach year.

The ground-breaking for the new Submillimeter Array marksthe formal return of Smithsonian astronomers to Hawai'i. In the early days of the Space Age, the SmithsonianAstrophysical Observatory established a satellite-trackingstation on the rim of Hale'akala on the island of Maui.The tracking camera was part of a 12-station internationalnetwork that supported the national space program from1957 to 1980.

Beyond astronomy, Smithsonian's research connections toHawai'i date back more than a century, with studies inbiology, botany, and ornithology conducted in cooperationwith the University of Hawai'i, other local institutions,and individual researchers.

 
 
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