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CfA 1.2 M Millimeter-Wave Telescope
The 1.2 meter Millimeter-Wave Telescope at the Harvard-Smithsonian Center for Astrophysics, Center for Astrophysics Harvard & Smithsonian and its twin instrument at Cerro Tololo Inter-American Observatory, CTIO in Chile have been studying the distribution and properties of molecular clouds in our galaxy and its nearest neighbours since the 1970s. The telescope is nicknamed "The Mini" because of its unusually small size. At the time it was built, it was the smallest radio telescope in the world. Together, "The Mini" and its twin in Chile have obtained what is by far the most extensive, uniform, and widely used galactic survey of interstellar carbon monoxide. "The Mini" is currently in operation from October to May each year. In the early 1970s, an astronomer at the Goddard Institute of Space Studies in New York (State), New York named Patrick Thaddeus shattered centuries of precedent in the field of astronomy and bucked a trend dating all the way back to Galileo when he decided ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
X-factor (astrophysics)
The X-factor in astrophysics, often labeled XCO, is an empirically determined proportionality constant which converts carbon monoxide (CO) emission line brightness to molecular hydrogen (H2) mass. Origin The term X-factor was coined in a 1983 paper titled "Gamma-rays from atomic and molecular gas in the first galactic quadrant" and published in ''The Astrophysical Journal''. Calibration Calibrating XCO requires an independent method of determining the amount of molecular hydrogen in a given astrophysical region. While direct emission from molecular hydrogen is difficult to observe, there are other ways of inferring molecular hydrogen mass, outlined below. * The mass of an individual molecular cloud can be inferred from its velocity dispersion. Assuming that the cloud is self gravitating and virialized, and that nearly all of the gas mass is molecular hydrogen, one obtains an estimate of the cloud's H2 mass. * H2 mass can be estimated through gamma ray observations, where gam ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Manhattan
Manhattan (), known regionally as the City, is the most densely populated and geographically smallest of the five Boroughs of New York City, boroughs of New York City. The borough is also coextensive with New York County, one of the List of counties in New York, original counties of the U.S. state of New York (state), New York. Located near the southern tip of New York State, Manhattan is based in the Eastern Time Zone and constitutes both the geographical and demographic center of the Northeast megalopolis and the urban core of the New York metropolitan area, the largest metropolitan area in the world by urban area, urban landmass. Over 58 million people live within 250 miles of Manhattan, which serves as New York City’s economic and administrative center, cultural identifier, and the city’s historical birthplace. Manhattan has been described as the cultural, financial, Media in New York City, media, and show business, entertainment capital of the world, is considered a saf ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Columbia University
Columbia University (also known as Columbia, and officially as Columbia University in the City of New York) is a private research university in New York City. Established in 1754 as King's College on the grounds of Trinity Church in Manhattan, Columbia is the oldest institution of higher education in New York and the fifth-oldest institution of higher learning in the United States. It is one of nine colonial colleges founded prior to the Declaration of Independence. It is a member of the Ivy League. Columbia is ranked among the top universities in the world. Columbia was established by royal charter under George II of Great Britain. It was renamed Columbia College in 1784 following the American Revolution, and in 1787 was placed under a private board of trustees headed by former students Alexander Hamilton and John Jay. In 1896, the campus was moved to its current location in Morningside Heights and renamed Columbia University. Columbia scientists and scholars hav ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arc-minute
A minute of arc, arcminute (arcmin), arc minute, or minute arc, denoted by the symbol , is a unit of angular measurement equal to of one degree. Since one degree is of a turn (or complete rotation), one minute of arc is of a turn. The nautical mile (nmi) was originally defined as the arc length of a minute of latitude on a spherical Earth, so the actual Earth circumference is very near . A minute of arc is of a radian. A second of arc, arcsecond (arcsec), or arc second, denoted by the symbol , is of an arcminute, of a degree, of a turn, and (about ) of a radian. These units originated in Babylonian astronomy as sexagesimal subdivisions of the degree; they are used in fields that involve very small angles, such as astronomy, optometry, ophthalmology, optics, navigation, land surveying, and marksmanship. To express even smaller angles, standard SI prefixes can be employed; the milliarcsecond (mas) and microarcsecond (μas), for instance, are commonly used in astrono ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tom Dame
Thomas M. Dame is Director of the Radio Telescope Data Center at the Center for Astrophysics Harvard & Smithsonian, a Senior Radio Astronomer at the Smithsonian Astrophysical Observatory, and a Lecturer on Astronomy at Harvard University. He is best known for mapping the Milky Way galaxy in Carbon Monoxide and for the discovery of both the Far 3 kpc Arm and the Outer Scutum–Centaurus Arm of the Milky Way. Education Dame graduated from Boston University in 1976 with a BA in Astronomy and Physics. He earned his Master's degrees and Ph.D. from Columbia University. His dissertation, earned under Patrick Thaddeus in 1983, was titled ''Molecular Clouds and Galactic Spiral Structure ''. Career After earning his doctorate, Dame worked as the National Research Council resident research associate at the Goddard Institute for Space Studies from 1983 to 1984 and then as a research associate at the Columbia University Department of Astronomy. He moved to Harvard University with Thaddeus in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Smithsonian Astrophysical Observatory
The Smithsonian Astrophysical Observatory (SAO) is a research institute of the Smithsonian Institution, concentrating on astrophysical studies including galactic and extragalactic astronomy, cosmology, solar, earth and planetary sciences, theory and instrumentation, using observations at wavelengths from the highest energy gamma rays to the radio, along with gravitational waves. Established in Washington, D.C., in 1890, the SAO moved its headquarters in 1955 to Cambridge, Massachusetts, where its research is a collaboration with the Harvard College Observatory (HCO) and the Harvard University Department of Astronomy. In 1973, the Smithsonian and Harvard formalized the collaboration as the Center for Astrophysics , Harvard & Smithsonian (CfA) under a single Director. History Samuel Pierpont Langley, the third Secretary of the Smithsonian, founded the Smithsonian Astrophysical Observatory on the south yard of the Smithsonian Castle (on the U.S. National Mall) o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Harvard University
Harvard University is a private Ivy League research university in Cambridge, Massachusetts. Founded in 1636 as Harvard College and named for its first benefactor, the Puritan clergyman John Harvard, it is the oldest institution of higher learning in the United States and one of the most prestigious and highly ranked universities in the world. The university is composed of ten academic faculties plus Harvard Radcliffe Institute. The Faculty of Arts and Sciences offers study in a wide range of undergraduate and graduate academic disciplines, and other faculties offer only graduate degrees, including professional degrees. Harvard has three main campuses: the Cambridge campus centered on Harvard Yard; an adjoining campus immediately across Charles River in the Allston neighborhood of Boston; and the medical campus in Boston's Longwood Medical Area. Harvard's endowment is valued at $50.9 billion, making it the wealthiest academic institution in the world. Endo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Emeritus
''Emeritus'' (; female: ''emerita'') is an adjective used to designate a retired chair, professor, pastor, bishop, pope, director, president, prime minister, rabbi, emperor, or other person who has been "permitted to retain as an honorary title the rank of the last office held". In some cases, the term is conferred automatically upon all persons who retire at a given rank, but in others, it remains a mark of distinguished service awarded selectively on retirement. It is also used when a person of distinction in a profession retires or hands over the position, enabling their former rank to be retained in their title, e.g., "professor emeritus". The term ''emeritus'' does not necessarily signify that a person has relinquished all the duties of their former position, and they may continue to exercise some of them. In the description of deceased professors emeritus listed at U.S. universities, the title ''emeritus'' is replaced by indicating the years of their appointmentsThe Protoc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Milky Way Multispectral SMIL
Milky is an Italian dance music production group consisting of producers Giordano Trivellato and Giuliano Sacchetto, with Italian singer Giuditta serving as their lead singer on their album ''Star''. Although Giuditta Gazza was the singer on the recordings, a model, the Egyptian-born and German-raised Sabrina Elahl, was used for the music video for the " Just the Way You Are" single. The same model was used for the cover. Elahl's voice did not appear on any of Milky's recordings, where all songs were sung by Giuditta. Giuditta can be seen on the " [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scutum–Centaurus Arm
The Scutum–Centaurus Arm, also known as Scutum-Crux arm, is a long, diffuse curving streamer of stars, gas and dust that spirals outward from the proximate end of the Milky Way's central bar. The Milky Way has been posited since the 1950s to have four spiral arms — numerous studies contest or nuance this number. In 2008, observations using the Spitzer Space Telescope failed to show the expected density of red clump giants in the direction of the Sagittarius and Norma arms. In January 2014, a 12-year study into the distribution and lifespan of massive stars and a 2013-reporting study of the distribution of masers and open clusters both found corroboratory, though would not state irrefutable, evidence for four principal spiral arms. The Scutum–Centaurus Arm lies between the minor Carina–Sagittarius Arm and the major Perseus Arm. The Scutum–Centaurus Arm starts near the core as the ''Scutum Arm'', then gradually turns into the ''Centaurus Arm''. The region where the S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Galactic Center
The Galactic Center or Galactic Centre is the rotational center, the barycenter, of the Milky Way galaxy. Its central massive object is a supermassive black hole of about 4 million solar masses, which is called Sagittarius A*, a compact radio source which is almost exactly at the galactic rotational center. The Galactic Center is approximately away from Earth in the direction of the constellations Sagittarius, Ophiuchus, and Scorpius, where the Milky Way appears brightest, visually close to the Butterfly Cluster (M6) or the star Shaula, south to the Pipe Nebula. There are around 10 million stars within one parsec of the Galactic Center, dominated by red giants, with a significant population of massive supergiants and Wolf–Rayet stars from star formation in the region around 1 million years ago. The core stars are a small part within the much wider galactic bulge. Discovery Because of interstellar dust along the line of sight, the Galactic Center cannot b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
