* Astronomy

The Submillimeter Array
Astronomers are meeting this week in Cambridge, Mass., to discuss recent advances generated by a new astronomical facility-the Submillimeter Array (SMA) on Mauna Kea, Hawaii.
A joint project of the Smithsonian Astrophysical Observatory (SAO) and the Academia Sinica Institute of Astronomy and Astrophysics (ASIAA), the SMA has opened a new window onto the cosmos by observing radiation from some of the coldest, dustiest, and most distant objects in the universe.


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SMA observations have clarified the nature of mysterious primordial galaxies billions of light-years away.
The galaxy GN20 is clearly detected in the SMA image shown at far left. The middle panel shows SMA contours overlaying an image taken at a wavelength of 4.5 microns by IRAC on the Spitzer Space Telescope. The right panel shows SMA contours overlaying an image from the Hubble Space Telescope. Clearly, SMA can see what Hubble cannot. Credit: Daisuke Iono (SAO)

"The SMA is the latest in a long line of cutting-edge research facilities developed by the Smithsonian. It demonstrates the Smithsonian's commitment to remaining at the frontier of scientific research" - Jim Moran, SMA director.

Atop the highest volcanic peak in the Hawaiian Island chain, the SMA explores the universe by detecting light at wavelengths (or colours) that are not visible to the human eye. It receives millimetre and submillimetre radiation, so named because the wavelength ranges from 0.3 to 1.7 millimetres, or 0.01 to 0.07 inches. The SMA combines signals from eight 6-meter-diameter movable antennas to achieve very high resolution, comparable to the best ground-based optical telescopes.


The SMA has clarified the nature of these mystery objects, revealing that many submillimetre galaxies are undergoing intense bursts of star formation hidden behind massive amounts of dust.

"The SMA literally has seen what Hubble can't see. The unique capabilities of the SMA allow it to detect and make high-resolution images of these young galaxies" - astronomer Daisuke Iono, Harvard-Smithsonian Centre for Astrophysics (CfA).
"With the SMA, we immediately pinpointed the exact location of two galaxies that were actively forming stars at an exceptional rate more than 10 billion years ago" - astronomer Alison Peck (CfA).

SMA observations are expected to help clarify the nature of many cosmic objects from distant galaxies to nearby star forming regions. It will examine those objects at high angular resolution in preparation for more detailed and more sensitive studies by its eventual successor, the Atacama Large Millimetre Array (ALMA).

"SMA is blazing a path of discovery across northern skies that ALMA will follow as it brings a depth of understanding to planet, star and galaxy formation in the southern skies" - Al Wootten, ALMA project scientist.

Headquartered in Cambridge, Mass., the Harvard-Smithsonian Centre for Astrophysics (CfA) is a joint collaboration between the Smithsonian Astrophysical Observatory and the Harvard College Observatory. CfA scientists, organized into six research divisions, study the origin, evolution and ultimate fate of the universe.