| 词条 | Submillimeter Array |
| 释义 |
The Submillimeter Array (SMA) consists of eight {{convert|6|m|adj=on|sp=us}} diameter radio telescopes arranged as an interferometer for submillimeter wavelength observations. It is the first purpose-built submillimeter interferometer, constructed after successful interferometry experiments using the pre-existing {{convert|15|m|0|adj=on|sp=us}} James Clerk Maxwell Telescope and {{convert|10.4|m|1|adj=on|sp=us}} Caltech Submillimeter Observatory as an interferometer. All three of these observatories are located at Mauna Kea Observatory on Mauna Kea, Hawaii, and can be operated together as a ten element interferometer in the 230 and 345 GHz bands (eSMA, for extended Submillimeter Array). The baseline lengths presently in use range from {{convert|16|to|508|m|0|sp=us}}, and up to {{convert|783|m|0|sp=us}} for eSMA operations. The radio frequencies accessible to this telescope range from {{convert|180-418|GHz|mm}} which includes rotational transitions of dozens of molecular species as well as continuum emission from interstellar dust grains. Although the array is capable of operating both day and night, most of the observations take place at nighttime when the atmospheric phase stability is best. The SMA is jointly operated by the Smithsonian Astrophysical Observatory and the Academia Sinica Institute of Astronomy and Astrophysics. Science with the SMAThe SMA is a multi-purpose instrument which can be used to observe diverse celestial phenomena. The SMA excels at observations of dust and gas with temperatures only a few tens of kelvins above absolute zero. Objects with such temperatures typically emit the bulk of their radiation at wavelengths between a few hundred micrometers and a few millimeters, which is the wavelength range in which the SMA can observe. Commonly observed classes of objects include star-forming molecular clouds in our own and other galaxies, highly redshifted galaxies, evolved stars, and the Galactic Center. Occasionally, bodies in the Solar System, such as planets, asteroids, comets and moons, are observed. The SMA has been used to discover that Pluto is {{convert|10|K-change|0|lk=in}} cooler than expected.[1] It was the first radio telescope to resolve Pluto and Charon as separate objects.[2] The SMA is a part of the Event Horizon Telescope, which observes nearby supermassive black holes with an angular resolution comparable to the size of the object's event horizon. Gallery{{Gallery|width=300 |Image:Submillimeter Array Night.jpg|The Submillimeter Array at night in 2015, lit by flash |Image:Mk submm array.jpg|The Array under construction in 2002 }} See also
References1. ^{{cite web |url=http://www.cfa.harvard.edu/press/2006/pr200601.html |title=A planet colder than it should be |work=Harvard.edu |date=2006-01-03 |accessdate=2008-11-25}} 2. ^{{cite journal |title=Sub-Arcsecond Scale Imaging of the Pluto/Charon Binary System at 1.4 mm |journal=Bulletin of the American Astronomical Society |first1=Mark A |last1=Gurwell |first2=Bryan J |last2=Butler |volume=37 |page=743 |date=August 2005 |bibcode=2005DPS....37.5501G}} External links
5 : Radio telescopes|Submillimetre telescopes|Interferometric telescopes|Astronomical observatories in Hawaii|Buildings and structures in Hawaii County, Hawaii |
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