Panoramic view of the Chajnantor plateau, spanning about 180 degrees from north (on the left) to south (on the right) shows the antennas of the Atacama Large Millimeter Array.
The most significant limitations to the detection of astronomical emission at submillimetre wavelengths with ground-based observatories are atmospheric emission, noise and attenuation. Like the infrared, the submillimetre atmosphere is dominated by numerous water vapourabsorption bands and it is only through "windows" between these bands that observations are possible. The ideal submillimetre observing site is dry, cool, has stable weather conditions and is away from urban population centres. Only a handful of such have been sites identified. They include Mauna Kea (Hawaii, United States), the Llano de Chajnantor Observatory on the Atacama Plateau (Chile), the South Pole, and Hanle in India (the Himalayan site of the Indian Astronomical Observatory). Comparisons show that all four sites are excellent for submillimetre astronomy, and of these sites Mauna Kea is the most established and arguably the most accessible. There has been some recent interest in high-altitude Arctic sites, particularly Summit Station in Greenland where the PWV (precipitable water vapor) measure is always better than at Mauna Kea (however Mauna Kea's equatorial latitude of 19 degrees means it can observe more of the southern skies than Greenland).[1][2]
The Llano de Chajnantor Observatory site hosts the Atacama Pathfinder Experiment (APEX), the largest submillimetre telescope operating in the southern hemisphere, and the world's largest ground based astronomy project, the Atacama Large Millimeter Array (ALMA), an interferometer for submillimetre wavelength observations made of 54 12-metre and 12 7-metre radio telescopes. The Submillimeter Array (SMA) is another interferometer, located at Mauna Kea, consisting of eight 6-metre diameter radio telescopes. The largest existing submillimetre telescope, the James Clerk Maxwell Telescope, is also located on Mauna Kea.
From the stratosphere
With high-altitude balloons and aircraft, one can get above even more of the atmosphere. The BLAST experiment and SOFIA are two examples, respectively, although SOFIA can also handle near infrared observations.
Space-based observations at the submillimetre wavelengths remove the ground-based limitations of atmospheric absorption. The first submillimeter telescope in space was the Soviet BST-1M, located in the scientific equipment compartment of the Salyut-6 orbital station. It was equipped with a mirror with a diameter of 1.5 m and was intended for astrophysical research in the ultraviolet (0.2 - 0.36 microns), infrared (60 - 130 microns) and submillimeter (300 - 1000 microns) spectral regions, which are of interest to those who are interested in which makes it possible to study molecular clouds in space, as well as obtain information about the processes taking place in the upper layers of the earth's atmosphere.
The Submillimeter Wave Astronomy Satellite (SWAS) was launched into low Earth orbit on December 5, 1998 as one of NASA's Small Explorer Program (SMEX) missions. The mission of the spacecraft is to make targeted observations of giant molecular clouds and dark cloud cores. The focus of SWAS is five spectral lines: water (H2O), isotopic water (H218O), isotopic carbon monoxide (13CO), molecular oxygen (O2), and neutral carbon (C I).
The SWAS satellite was repurposed in June, 2005 to provide support for the NASA Deep Impact mission. SWAS provided water production data on the comet until the end of August 2005.
The European Space Agency launched a space-based mission known as the Herschel Space Observatory (formerly called Far Infrared and Sub-millimetre Telescope or FIRST) in 2009. Herschel deployed the largest mirror ever launched into space (until December 2021, with the launch of the near-infrared James Webb Space Telescope) and studied radiation in the far infrared and submillimetre wavebands. Rather than an Earth orbit, Herschel entered into a Lissajous orbit around L2, the second Lagrangian point of the Earth-Sun system. L2 is located approximately 1.5 million km from Earth and the placement of Herschel there lessened the interference by infrared and visible radiation from the Earth and Sun. Herschel's mission focused primarily on the origins of galaxies and galactic formation.
^JPL: Herschel Space Observatory: Related Missions
External links
Arizona Radio Observatory page on Submillimeter Astronomy
Atacama Pathfinder Experiment (APEX) Home Page
Atacama Large Millimeter Array (ALMA) Home Page
SWAS Home Page
Herschel Space Observatory
March 03, 2023
submillimetre, astronomy, submillimeter, telescope, redirects, here, telescope, formally, known, submillimeter, telescope, heinrich, hertz, submillimeter, telescope, this, article, needs, additional, citations, verification, please, help, improve, this, articl. Submillimeter telescope redirects here For the telescope formally known as the Submillimeter Telescope see Heinrich Hertz Submillimeter Telescope This article needs additional citations for verification Please help improve this article by adding citations to reliable sources Unsourced material may be challenged and removed Find sources Submillimetre astronomy news newspapers books scholar JSTOR September 2010 Learn how and when to remove this template message Submillimetre astronomy or submillimeter astronomy see spelling differences is the branch of observational astronomy that is conducted at submillimetre wavelengths i e terahertz radiation of the electromagnetic spectrum Astronomers place the submillimetre waveband between the far infrared and microwave wavebands typically taken to be between a few hundred micrometres and a millimetre It is still common in submillimetre astronomy to quote wavelengths in microns the old name for micrometre The Caltech Submillimeter Observatory at Mauna Kea Observatory was commissioned in 1988 and has a 10 4 m 34 ft dish Using submillimetre observations astronomers examine molecular clouds and dark cloud cores with a goal of clarifying the process of star formation from earliest collapse to stellar birth Submillimetre observations of these dark clouds can be used to determine chemical abundances and cooling mechanisms for the molecules which comprise them In addition submillimetre observations give information on the mechanisms for the formation and evolution of galaxies Contents 1 From the ground 2 From the stratosphere 3 From orbit 4 See also 5 References 6 External linksFrom the ground Edit Panoramic view of the Chajnantor plateau spanning about 180 degrees from north on the left to south on the right shows the antennas of the Atacama Large Millimeter Array The most significant limitations to the detection of astronomical emission at submillimetre wavelengths with ground based observatories are atmospheric emission noise and attenuation Like the infrared the submillimetre atmosphere is dominated by numerous water vapour absorption bands and it is only through windows between these bands that observations are possible The ideal submillimetre observing site is dry cool has stable weather conditions and is away from urban population centres Only a handful of such have been sites identified They include Mauna Kea Hawaii United States the Llano de Chajnantor Observatory on the Atacama Plateau Chile the South Pole and Hanle in India the Himalayan site of the Indian Astronomical Observatory Comparisons show that all four sites are excellent for submillimetre astronomy and of these sites Mauna Kea is the most established and arguably the most accessible There has been some recent interest in high altitude Arctic sites particularly Summit Station in Greenland where the PWV precipitable water vapor measure is always better than at Mauna Kea however Mauna Kea s equatorial latitude of 19 degrees means it can observe more of the southern skies than Greenland 1 2 The Llano de Chajnantor Observatory site hosts the Atacama Pathfinder Experiment APEX the largest submillimetre telescope operating in the southern hemisphere and the world s largest ground based astronomy project the Atacama Large Millimeter Array ALMA an interferometer for submillimetre wavelength observations made of 54 12 metre and 12 7 metre radio telescopes The Submillimeter Array SMA is another interferometer located at Mauna Kea consisting of eight 6 metre diameter radio telescopes The largest existing submillimetre telescope the James Clerk Maxwell Telescope is also located on Mauna Kea From the stratosphere EditWith high altitude balloons and aircraft one can get above even more of the atmosphere The BLAST experiment and SOFIA are two examples respectively although SOFIA can also handle near infrared observations From orbit EditComparison 3 Name Year Wavelength ApertureHuman Eye 0 39 0 75 mm 0 01 mSWAS 1998 540 610 mm 0 55 0 7Herschel 2009 55 672 mm 3 5 mSpace based observations at the submillimetre wavelengths remove the ground based limitations of atmospheric absorption The first submillimeter telescope in space was the Soviet BST 1M located in the scientific equipment compartment of the Salyut 6 orbital station It was equipped with a mirror with a diameter of 1 5 m and was intended for astrophysical research in the ultraviolet 0 2 0 36 microns infrared 60 130 microns and submillimeter 300 1000 microns spectral regions which are of interest to those who are interested in which makes it possible to study molecular clouds in space as well as obtain information about the processes taking place in the upper layers of the earth s atmosphere The Submillimeter Wave Astronomy Satellite SWAS was launched into low Earth orbit on December 5 1998 as one of NASA s Small Explorer Program SMEX missions The mission of the spacecraft is to make targeted observations of giant molecular clouds and dark cloud cores The focus of SWAS is five spectral lines water H2O isotopic water H218O isotopic carbon monoxide 13CO molecular oxygen O2 and neutral carbon C I The SWAS satellite was repurposed in June 2005 to provide support for the NASA Deep Impact mission SWAS provided water production data on the comet until the end of August 2005 The European Space Agency launched a space based mission known as the Herschel Space Observatory formerly called Far Infrared and Sub millimetre Telescope or FIRST in 2009 Herschel deployed the largest mirror ever launched into space until December 2021 with the launch of the near infrared James Webb Space Telescope and studied radiation in the far infrared and submillimetre wavebands Rather than an Earth orbit Herschel entered into a Lissajous orbit around L2 the second Lagrangian point of the Earth Sun system L2 is located approximately 1 5 million km from Earth and the placement of Herschel there lessened the interference by infrared and visible radiation from the Earth and Sun Herschel s mission focused primarily on the origins of galaxies and galactic formation See also EditEvent Horizon Telescope Terahertz radiation Far infrared astronomy SCUBA 2 All Sky Survey Radio window Infrared window Optical window Category Submillimetre telescopesReferences Edit Recent Interest in Eureka on Ellesmere Island as a Submillimetre Observing Site PDF Archived from the original PDF on 2015 07 03 ASIAA sub mm VLBI Project PDF JPL Herschel Space Observatory Related MissionsExternal links EditArizona Radio Observatory page on Submillimeter Astronomy Atacama Pathfinder Experiment APEX Home Page Atacama Large Millimeter Array ALMA Home Page SWAS Home Page Herschel Space Observatory Retrieved from https en wikipedia org w index php title Submillimetre astronomy amp oldid 1062095053, wikipedia, wiki, book, books, library,
