A radio telescope is a specialized antenna and radio receiver used to detect radio waves from astronomical radio sources in the sky. Radio telescopes are the main observing instrument used in radio astronomy, which studies the radio frequency portion of the electromagnetic spectrum emitted by astronomical objects, just as optical telescopes are the main observing instrument used in traditional optical astronomy which studies the light wave portion of the spectrum coming from astronomical objects. Unlike optical telescopes, radio telescopes can be used in the daytime as well as at night.
Radio astronomy is a subfield of astronomy that studies celestial objects at radio frequencies. The first detection of radio waves from an astronomical object was in 1933, when Karl Jansky at Bell Telephone Laboratories reported radiation coming from the Milky Way. Subsequent observations have identified a number of different sources of radio emission. These include stars and galaxies, as well as entirely new classes of objects, such as radio galaxies, quasars, pulsars, and masers. The discovery of the cosmic microwave background radiation, regarded as evidence for the Big Bang theory, was made through radio astronomy.
The National Radio Astronomy Observatory (NRAO) is a federally funded research and development center of the United States National Science Foundation operated under cooperative agreement by Associated Universities, Inc. for the purpose of radio astronomy. NRAO designs, builds, and operates its own high-sensitivity radio telescopes for use by scientists around the world.
The Very Long Baseline Array (VLBA) is a system of ten radio telescopes which are operated remotely from their Array Operations Center located in Socorro, New Mexico, as a part of the National Radio Astronomy Observatory (NRAO). These ten radio antennas work together as an array that forms the longest system in the world that uses very long baseline interferometry. The longest baseline available in this interferometer is about 8,611 kilometers (5,351 mi).
The Atacama Large Millimeter/submillimeter Array (ALMA) is an astronomical interferometer of 66 radio telescopes in the Atacama Desert of northern Chile, which observe electromagnetic radiation at millimeter and submillimeter wavelengths. The array has been constructed on the 5,000 m (16,000 ft) elevation Chajnantor plateau - near the Llano de Chajnantor Observatory and the Atacama Pathfinder Experiment. This location was chosen for its high elevation and low humidity, factors which are crucial to reduce noise and decrease signal attenuation due to Earth's atmosphere. ALMA provides insight on star birth during the early Stelliferous era and detailed imaging of local star and planet formation.
The Caltech Submillimeter Observatory (CSO) was a 10.4-meter (34 ft) diameter submillimeter wavelength telescope situated alongside the 15-meter (49 ft) James Clerk Maxwell Telescope (JCMT) at Mauna Kea Observatories. It was engaged in submillimeter astronomy, of the terahertz radiation band. The telescope closed on September 18, 2015. As of April 2019, the telescope is set to be dismantled and its site remediated in the near future as part of the Mauna Kea Comprehensive Management Plan.
Owens Valley Radio Observatory (OVRO) is a radio astronomy observatory located near Big Pine, California (US) in Owens Valley. It lies east of the Sierra Nevada, approximately 350 kilometers (220 mi) north of Los Angeles and 20 kilometers (12 mi) southeast of Bishop. It was established in 1956, and is owned and operated by the California Institute of Technology (Caltech). The Owens Valley Solar Array portion of the observatory has been operated by New Jersey Institute of Technology (NJIT) since 1997.
The Sunyaev–Zeldovich Array (SZA) in California is an array of eight 3.5 meter telescopes that was operated as part of the now closed Combined Array for Research in Millimeter-wave Astronomy (CARMA). Its initial goals were to survey the Cosmic Microwave Background (CMB) in order to measure its fine-scale anisotropies and to find clusters of galaxies. The survey was completed in 2007, and the array is now used primarily to characterize clusters via the Sunyaev–Zeldovich effect. Observations commenced at the SZA in April 2005.
The Combined Array for Research in Millimeter-wave Astronomy (CARMA) was an astronomical instrument comprising 23 radio telescopes, dedicated in 2006. These telescopes formed an astronomical interferometer where all the signals are combined in a purpose-built computer to produce high-resolution astronomical images. The telescopes ceased operation in April 2015 and were relocated to the Owens Valley Radio Observatory for storage.
Institut de Radioastronomie Millimetrique (IRAM) is an international research institute and Europe's leading center for radio astronomy at millimeter wavelengths. Its mission is to explore the universe, study its origins and its evolution with two of the most advanced radio facilities in the world:
The Hat Creek Radio Observatory (HCRO) is operated by SRI International in the Western United States. The observatory is home to the Allen Telescope Array designed and owned by the SETI Institute in Mountain View, CA.
Llano de Chajnantor Observatory is the name for a group of astronomical observatories located at an altitude of over 4,800 m (15,700 ft) in the Atacama Desert of northern Chile. The site is in the Antofagasta Region approximately 50 kilometres (31 mi) east of the town of San Pedro de Atacama. The exceptionally arid climate of the area is inhospitable to humans, but creates an excellent location for millimeter, submillimeter, and mid-infrared astronomy. This is because water vapour absorbs and attenuates submillimetre radiation. Llano de Chajnantor is home to the largest and most expensive astronomical telescope project in the world, the Atacama Large Millimeter Array (ALMA). Llano de Chajnantor and the surrounding area has been designated as the Chajnantor Science Reserve by the government of Chile.
Associated Universities, Inc. (AUI) is a research management corporation that builds and operates facilities for the research community. It is a not-for-profit 501(c)(3) corporation headquartered in Washington, D.C., United States. The current president is Adam Cohen. The corporation's major current operating unit is the National Radio Astronomy Observatory, which it operates under a Cooperative Agreement with the National Science Foundation.
The Plateau de Bure Interferometer (PdBI) was a six-antenna interferometer on the Pic de Bure (2550 m) in the French Alps, operated by the Institut de radioastronomie millimétrique. In 2014, it has been replaced by the Northern Extended Millimeter Array. It was specifically designed for millimetre-wave observations and specialises in studies of line emission from molecular gas and radio continuum of cold dust.
An astronomical interferometer or telescope array is a set of separate telescopes, mirror segments, or radio telescope antennas that work together as a single telescope to provide higher resolution images of astronomical objects such as stars, nebulas and galaxies by means of interferometry. The advantage of this technique is that it can theoretically produce images with the angular resolution of a huge telescope with an aperture equal to the separation, called baseline, between the component telescopes. The main drawback is that it does not collect as much light as the complete instrument's mirror. Thus it is mainly useful for fine resolution of more luminous astronomical objects, such as close binary stars. Another drawback is that the maximum angular size of a detectable emission source is limited by the minimum gap between detectors in the collector array.
John E. Carlstrom is an American astrophysicist, and Professor, Departments of Astronomy and Astrophysics, and Physics, at the University of Chicago.
The Radio Astronomy Lab (RAL) is an Organized Research Unit (ORU) within the Astronomy Department at the University of California, Berkeley. It was founded by faculty member Harold Weaver in 1958. Until 2012, RAL maintained a radio astronomy observatory at Hat Creek, near Mt. Lassen. It continues to support on-campus laboratory facilities in Campbell Hall. From 1998 to 2012, the RAL collaborated with the SETI Institute of Mountain View California to design, build and operate the Allen Telescope Array (ATA).
The Large Latin American Millimeter Array (LLAMA) is a single-dish 12 m Nasmyth optics antenna which is under construction in the Puna de Atacama desert in the Province of Salta, Argentina, next to the Qubic experiment. The primary mirror accuracy will allow observation from 40 GHz up to 900 GHz. After installation it will be able to join other similar instruments to perform Very Large Base Line Interferometry or to work in standalone mode. Financial support is provided by the Argentinian and Brazilian governments. The total cost of construction, around US$20 million, and operation as well as the telescope time use will be shared equally by the two countries. Construction planning started in July 2014 after the formal signature of an agreement between the main institutions involved.
The Northern Extended Millimeter Array (NOEMA) is one of the largest astronomical facilities on European ground and the most powerful radio telescope in the Northern Hemisphere operating at millimeter wavelengths. It consists of a large array of twelve 15-meter antennas that can spread over distances of up to 1.7 kilometers, working together as a single telescope.
The Vermilion River Radio Observatory (VRO) was a research facility operated by the University of Illinois from 1959 to 1984, featuring a 400-foot (120 m) linear parabolic radio telescope. The 420-acre (170 ha) site was a pioneering facility in radio astronomy.
