The jansky is a non-SI unit of spectral flux density, or spectral irradiance, used especially in radio astronomy. It is equivalent to 10−26 watts per square metre per hertz.
Sir Martin Ryle was an English radio astronomer who developed revolutionary radio telescope systems and used them for accurate location and imaging of weak radio sources. In 1946 Ryle and Derek Vonberg were the first people to publish interferometric astronomical measurements at radio wavelengths. With improved equipment, Ryle observed the most distant known galaxies in the universe at that time. He was the first Professor of Radio Astronomy at the University of Cambridge, and founding director of the Mullard Radio Astronomy Observatory. He was Astronomer Royal from 1972 to 1982. Ryle and Antony Hewish shared the Nobel Prize for Physics in 1974, the first Nobel prize awarded in recognition of astronomical research. In the 1970s, Ryle turned the greater part of his attention from astronomy to social and political issues which he considered to be more urgent.
The Third Cambridge Catalogue of Radio Sources (3C) is an astronomical catalogue of celestial radio sources detected originally at 159 MHz, and subsequently at 178 MHz.
The Cavendish Astrophysics Group is based at the Cavendish Laboratory at the University of Cambridge. The group operates all of the telescopes at the Mullard Radio Astronomy Observatory except for the 32m MERLIN telescope, which is operated by Jodrell Bank.
The One-Mile Telescope at the Mullard Radio Astronomy Observatory (MRAO), Cambridge, UK is an array of radio telescopes designed to perform aperture synthesis interferometry.
The Mills Cross Telescope was a two-dimensional radio telescope built by Bernard Mills in 1954 at the Fleurs field station of the Australian Commonwealth Scientific and Industrial Research Organisation in the area known now as Badgerys Creek, about 40 km west of Sydney, New South Wales, Australia.
The Fourth Cambridge Survey (4C) is an astronomical catalogue of celestial radio sources as measured at 178 MHz using the 4C Array. It was published in two parts, in 1965 and 1967, by the Radio Astronomy Group of the University of Cambridge. References to entries in this catalogue use the prefix 4C followed by the declination in degrees, followed by a period, and then followed by the source number on that declination strip, e.g. 4C-06.23.
The 5C Survey of Radio Sources (5C) is an astronomical catalogue of celestial radio sources as measured at 408 MHz and 1407 MHz. It was published in a number of parts between 1975 and 1995 by the Radio Astronomy Group of the University of Cambridge. The One-Mile Telescope used to produce this catalogue had an angular resolutions of 80 arcseconds and 23 arcseconds at 408 MHz and 1407 MHz respectively, and catalogued radio sources as faint as 2 milli-Janskys, considerably fainter than any previously catalogued radio source.
The 9C survey at 15 GHz (9C) is an astronomical catalogue generated from the radio observations of the Ninth Cambridge survey at 15 GHz. It was published in 2003 by the Cavendish Astrophysics Group of the University of Cambridge. The catalogue was originally made in order to locate radio sources which were interfering with observations using the Very Small Array, but the catalogue has also proved useful for other astronomical programs.
The 8C Survey (8C) or Rees 38 MHz survey is an astronomical catalogue of celestial radio sources as measured at 38 MHz. It was published in 1990 by the Radio Astronomy Group of the University of Cambridge. Sources are labelled 8C HHMM+DDd where HHMM is the Right Ascension in hours and minutes, and DDd is the Declination in degrees and tenths of a degree, e.g. 8C 0014+861 for a source at Right Ascension 00 14 and 86.1 degrees Declination in 1950 coordinates.
The 6C Survey of Radio Sources (6C) is an astronomical catalogue of celestial radio sources as measured at 151-MHz. It was published between 1985 and 1993 by the Radio Astronomy Group of the University of Cambridge.
The Cambridge Interferometer was a radio telescope interferometer built by Martin Ryle and Antony Hewish in the early 1950s to the west of Cambridge. The interferometer consisted of an array of 4 fixed elements to survey the sky. It produced the two Cambridge catalogues of radio sources, discovering some of the most interesting astronomical objects known. The telescope was operated by the Radio Astronomy Group of Cambridge University.
The Second Cambridge Catalogue of Radio Sources (2C) was published in 1955 by John R Shakeshaft and colleagues. It comprised a list of 1936 sources between declinations -38 and +83, giving their right ascension, declination, both in 1950.0 coordinates, and flux density. The observations were made with the Cambridge Interferometer, at 81.5 MHz.
The source counts distribution of radio-sources from a radio-astronomical survey is the cumulative distribution of the number of sources (N) brighter than a given flux density (S). As it is usually plotted on a log-log scale its distribution is known as the log N – log S plot. It is one of several cosmological tests that were conceived in the 1930s to check the viability of and compare new cosmological models.
An astronomical survey is a general map or image of a region of the sky that lacks a specific observational target. Alternatively, an astronomical survey may comprise a set of many images or spectra of objects that share a common type or feature. Surveys are often restricted to one band of the electromagnetic spectrum due to instrumental limitations, although multiwavelength surveys can be made by using multiple detectors, each sensitive to a different bandwidth.
The First Cambridge Catalogue of Radio Sources (1C) refers to the catalogue listed in the article Ryle M, Smith F G & Elsmore B (1950) MNRAS vol 110 pp508-523 "A Preliminary Survey of Radio Stars in the Northern Hemisphere".
The Ohio Sky Survey was an astronomical survey of extragalactic radio sources. Data were taken between 1965 and 1971 using the Big Ear radio telescope at the Ohio State University Radio Observatory (OSURO), also known as the "Big Ear Radio Observatory (BERO)".
3C 286, also known by its position as 1328+307 or 1331+305, is a quasar at redshift 0.8493 with a radial velocity of 164,137 km/s. It is part of the Third Cambridge Catalogue of Radio Sources.
Hercules A is a bright astronomical radio source within the vicinity of the constellation Hercules corresponding to the galaxy 3C 348.
