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J. Richard Fisher
James Richard Fisher (born December 10, 1943) is an American astronomer. He received his Ph.D. in Astronomy in 1972 from the University of Maryland, College Park and his B.S. in Physics in 1965 from the Pennsylvania State University, University Park. Education and research Much of Fisher's career has involved radio astronomy instrumentation, including telescope feed design, radio frequency interference mitigation, and signal processing. He joined NRAO in 1972 at the Green Bank, West Virginia site. He was part of the team that conceived and designed the 100-meter Green Bank Telescope there. He moved to the Central Development Lab at the Charlottesville NRAO headquarters in 2005, where he retired in 2012 but continues to be active in instrumentation projects. In 1978 through 1980 he spent 18 months at the Radiophysics Laboratory of CSIRO in Sydney, Australia, and on the return trip spent 2 months at the Raman Research Institute in Bangalore, India. Along with R. Brent Tully, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Tully–Fisher Relation
In astronomy, the Tully–Fisher relation (TFR) is a widely verified empirical relationship between the mass or intrinsic luminosity of a spiral galaxy and its asymptotic rotation velocity or emission line width. Since the observed brightness of a galaxy is distance-dependent, the relationship can be used to estimate distances to galaxies from measurements of their rotational velocity. History The connection between rotational velocity measured spectroscopically and distance was first used in 1922 by Ernst Öpik to estimate the distance to the Andromeda Galaxy. In the 1970s, Balkowski, C., et al. measured 13 galaxies but focused on using the data to distinguish galaxy shapes rather than extract distances. The relationship was first published in 1977 by astronomers R. Brent Tully and J. Richard Fisher. The luminosity is calculated by multiplying the galaxy's apparent brightness by 4\pi d^2, where d is its distance from Earth, and the spectral-line width is measured using long- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
University Of Maryland, College Park
The University of Maryland, College Park (University of Maryland, UMD, or simply Maryland) is a public university, public Land-grant university, land-grant research university in College Park, Maryland, United States. Founded in 1856, UMD is the Flagship university, flagship institution of the University System of Maryland. It is known as the biggest university in the state of Maryland. UMD is the largest university in Maryland and the Washington metropolitan area. Its eleven schools and colleges offer over 200 degree-granting programs, including 113 undergraduate majors, 107 Master's degree, master's programs, and 83 Doctorate, doctoral programs. UMD's athletic teams are known as the Maryland Terrapins and compete in NCAA Division I as a member of the Big Ten Conference. A member of the Association of American Universities, The University of Maryland's proximity to Washington, D.C. has resulted in many research partnerships with the Federal government of the United States, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
NRAO
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. Locations Charlottesville, Virginia The NRAO headquarters is located on the campus of the University of Virginia in Charlottesville, Virginia. The North American ALMA Science Center and the NRAO Technology Center and Central Development Laboratory are also in Charlottesville. Green Bank, West Virginia NRAO was, until October 2016, the operator of the world's largest fully steerable radio telescope, the Robert C. Byrd Green Bank Telescope, which stands near Green Bank, West Virginia. The observatory contains several other telescopes, among them the telescope that utilizes an equatorial mount uncommon for radio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Green Bank, West Virginia
Green Bank is a census-designated place in Pocahontas County in West Virginia's Potomac Highlands inside the Allegheny Mountain Range. Green Bank is located along WV 28. Green Bank is home to the Green Bank Observatory and is also close to the Snowshoe Mountain ski resort. As of the 2020 census, its population was 141. The community was named for a green riverbank near the original town site. National Radio Quiet Zone Green Bank is located within the National Radio Quiet Zone, which means that radio transmissions are heavily restricted by law. This policy is enforced by a "radio policeman" who uses specialized equipment to detect signals from unauthorized electronics. Green Bank is home to the Green Bank Telescope, the world's largest fully steerable radio telescope, which was operated by the National Radio Astronomy Observatory (NRAO) until September 30, 2016. Since October 1, 2016, the Telescope has been operated by the Green Bank Observatory, which is no longer part of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Green Bank Telescope
The Robert C. Byrd Green Bank Telescope (GBT) in Green Bank, West Virginia, US is the world's largest fully steerable radio telescope, surpassing the Effelsberg 100-m Radio Telescope in Germany. The Green Bank site was part of the National Radio Astronomy Observatory (NRAO) until September 30, 2016. Since October 1, 2016, the telescope has been operated by the independent Green Bank Observatory. The telescope's name honors the late Senator Robert C. Byrd who represented West Virginia and who pushed the funding of the telescope through Congress. The Green Bank Telescope operates at meter to millimeter wavelengths. Its 100-meter diameter collecting area, unblocked aperture, and good surface accuracy provide superb sensitivity across the telescope's full 0.1–116 GHz operating range. The GBT is fully steerable, and 85 percent of the local celestial hemisphere is accessible. It is used for astronomy about 6500 hours every year, with 2000–3000 hours per year going to high ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Charlottesville
Charlottesville, colloquially known as C'ville, is an independent city in Virginia, United States. It is the seat of government of Albemarle County, which surrounds the city, though the two are separate legal entities. It is named after Queen Charlotte. At the 2020 census, the city's population was 46,553. The Bureau of Economic Analysis combines the City of Charlottesville with Albemarle County for statistical purposes, bringing its population to approximately 160,000. Charlottesville is the heart of the Charlottesville metropolitan area, which includes Albemarle, Fluvanna, Greene, and Nelson counties. Charlottesville was the home of two U.S. presidents, Thomas Jefferson and James Monroe. During their terms as Governors of Virginia, they lived in Charlottesville and traveled to and from Richmond, along the 71-mile historic Three Notch'd Road. Orange, located northeast of the city, was the hometown of President James Madison. The University of Virginia, founded by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Emission Line
A spectral line is a weaker or stronger region in an otherwise uniform and continuous spectrum. It may result from emission or absorption of light in a narrow frequency range, compared with the nearby frequencies. Spectral lines are often used to identify atoms and molecules. These "fingerprints" can be compared to the previously collected ones of atoms and molecules, and are thus used to identify the atomic and molecular components of stars and planets, which would otherwise be impossible. Types of line spectra Spectral lines are the result of interaction between a quantum system (usually atoms, but sometimes molecules or atomic nuclei) and a single photon. When a photon has about the right amount of energy (which is connected to its frequency) to allow a change in the energy state of the system (in the case of an atom this is usually an electron changing orbitals), the photon is absorbed. Then the energy will be spontaneously re-emitted, either as one photon at the same f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Astronomy And Astrophysics
''Astronomy & Astrophysics (A&A)'' is a monthly peer-reviewed scientific journal covering theoretical, observational, and instrumental astronomy and astrophysics. It is operated by an editorial team under the supervision of a board of directors representing 27 sponsoring countries plus a representative of the European Southern Observatory. The journal is published by EDP Sciences and the current editors-in-chief are Thierry Forveille and João Alves. History Origins ''Astronomy & Astrophysics'' was created as an answer to the publishing situation found in Europe in the 1960s. At that time, multiple journals were being published in several countries around the continent. These journals usually had a limited number of subscribers, and articles were written in languages other than English. They were less widely read than American and British journals and the research they reported had therefore less impact in the community. Starting in 1963, conversations between astronomers from ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Living People
Purpose: Because living persons may suffer personal harm from inappropriate information, we should watch their articles carefully. By adding an article to this category, it marks them with a notice about sources whenever someone tries to edit them, to remind them of WP:BLP (biographies of living persons) policy that these articles must maintain a neutral point of view, maintain factual accuracy, and be properly sourced. Recent changes to these articles are listed on Special:RecentChangesLinked/Living people. Organization: This category should not be sub-categorized. Entries are generally sorted by family name In many societies, a surname, family name, or last name is the mostly hereditary portion of one's personal name that indicates one's family. It is typically combined with a given name to form the full name of a person, although several give .... Maintenance: Individuals of advanced age (over 90), for whom there has been no new documentation in the last ten ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
University Of Maryland, College Park Alumni
A university () is an institution of tertiary education and research which awards academic degrees in several academic disciplines. ''University'' is derived from the Latin phrase , which roughly means "community of teachers and scholars". Universities typically offer both undergraduate and postgraduate programs. The first universities in Europe were established by Catholic monks. The University of Bologna (), Italy, which was founded in 1088, is the first university in the sense of: *being a high degree-awarding institute. *using the word (which was coined at its foundation). *having independence from the ecclesiastic schools and issuing secular as well as non-secular degrees (with teaching conducted by both clergy and non-clergy): grammar, rhetoric, logic, theology, canon law and notarial law.Hunt Janin: "The university in medieval life, 1179–1499", McFarland, 2008, , p. 55f.de Ridder-Symoens, Hilde''A History of the University in Europe: Volume 1, Universities in th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
