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Robert Jackson (scientist)
Robert Earl Jackson (born 1949) is a scientist, who, with Sandra M. Faber, in 1976 discovered the Faber–Jackson relation between the luminosity of an elliptical galaxy and the velocity dispersion in its center. Jackson was a graduate student at the University of California at Santa Cruz. As a Research Assistant for Faber, he contributed to the data analysis on the project that led to the Faber–Jackson relation (1976). Jackson received his Ph.D. in 1982 with the thesis titled "The Anisotropy of the Hubble Constant". From 1984 to 1999, he worked for Computer Sciences Corporation at the Space Telescope Science Institute in Baltimore, Maryland Baltimore ( , locally: or ) is the List of municipalities in Maryland, most populous city in the U.S. state of Maryland, fourth most populous city in the Mid-Atlantic (United States), Mid-Atlantic, and List of United States cities by popula .... References American astronomers 1949 births Living people {{US-astronomer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sandra M
Sandra or SANDRA may refer to: People * Sandra (given name) * Sandra (singer) (born 1962), German pop singer * Margaretha Sandra (1629–1674), Dutch soldier * Sandra (orangutan), who won the legal right to be defined as a "non-human person" Places * Șandra, a commune in Timiș County, Romania * Şandra, a village in Beltiug Commune, Satu Mare County, Romania * Sandra, Estonia, a village * 1760 Sandra, an asteroid Other uses * "Sandra" (song), a 1975 song by Barry Manilow * "Sandra", song by Idle Eyes, 1986 * ''Sandra'' (1924 film), a lost drama film * ''Sandra'' (1965 film), an Italian film * SANDRA (research project), part of the European Union's Framework Programmes for Research and Technological Development * Tropical Storm Sandra, several tropical cyclones * ''Sandra'' (podcast), a scripted fiction podcast starring Kristen Wiig and Alia Shawkat See also * Sandro (other) * Sandara Park Sandara Park ( English pronunciation: ; born November 12, 1984), al ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Faber–Jackson Relation
The Faber–Jackson relation provided the first empirical power-law relation between the luminosity L and the central stellar velocity dispersion \sigma of elliptical galaxy, and was presented by the astronomers Sandra M. Faber and Robert Earl Jackson in 1976. Their relation can be expressed mathematically as: : L \propto \sigma^ \gamma with the index \gamma approximately equal to 4. In 1962, Rudolph Minkowski had discovered and wrote that a "correlation between velocity dispersion and uminosityexists, but it is poor" and that "it seems important to extend the observations to more objects, especially at low and medium absolute magnitudes". This was important because the value of \gamma depends on the range of galaxy luminosities that is fitted, with a value of 2 for low-luminosity elliptical galaxies discovered by a team led by Roger Davies, and a value of 5 reported by Paul L. Schechter for luminous elliptical galaxies.Paul L. Schechter (1980)Mass-to-light ratios fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Luminosity
Luminosity is an absolute measure of radiated electromagnetic power (light), the radiant power emitted by a light-emitting object over time. In astronomy, luminosity is the total amount of electromagnetic energy emitted per unit of time by a star, galaxy, or other astronomical object. In SI units, luminosity is measured in joules per second, or watts. In astronomy, values for luminosity are often given in the terms of the luminosity of the Sun, ''L''⊙. Luminosity can also be given in terms of the astronomical magnitude system: the absolute bolometric magnitude (''M''bol) of an object is a logarithmic measure of its total energy emission rate, while absolute magnitude is a logarithmic measure of the luminosity within some specific wavelength range or filter band. In contrast, the term ''brightness'' in astronomy is generally used to refer to an object's apparent brightness: that is, how bright an object appears to an observer. Apparent brightness depends on both the lumin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Elliptical Galaxy
An elliptical galaxy is a type of galaxy with an approximately ellipsoidal shape and a smooth, nearly featureless image. They are one of the four main classes of galaxy described by Edwin Hubble in his Hubble sequence and 1936 work ''The Realm of the Nebulae'', with their intermediate scale disks, a subset of the "early-type" galaxy population. Most elliptical galaxies are composed of older, low-mass stars, with a sparse interstellar medium and minimal star formation activity, and they tend to be surrounded by large numbers of globular clusters. Elliptical galaxies are believed to make up approximately 10–15% of galaxies in the Virgo Supercluster, and they are not the dominant type of galaxy in the universe overall. They are preferentially found close to the centers of galaxy clusters. Elliptical galaxies range in size from dwarf ellipticals with tens of millions of stars, to supergiants of over one hundred trillion stars that dominate their galaxy clusters. Original ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Velocity
Velocity is the directional speed of an object in motion as an indication of its rate of change in position as observed from a particular frame of reference and as measured by a particular standard of time (e.g. northbound). Velocity is a fundamental concept in kinematics, the branch of classical mechanics that describes the motion of bodies. Velocity is a physical vector quantity; both magnitude and direction are needed to define it. The scalar absolute value (magnitude) of velocity is called , being a coherent derived unit whose quantity is measured in the SI (metric system) as metres per second (m/s or m⋅s−1). For example, "5 metres per second" is a scalar, whereas "5 metres per second east" is a vector. If there is a change in speed, direction or both, then the object is said to be undergoing an ''acceleration''. Constant velocity vs acceleration To have a ''constant velocity'', an object must have a constant speed in a constant direction. Constant direction cons ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jones & Bartlett Learning
Jones & Bartlett Learning, a division of Ascend Learning, is a scholarly publisher. The name comes from Donald W. Jones, the company's founder, and Arthur Bartlett, the first editor. History In 1988, the company was named by ''New England Business Magazine'' as one of the 100 fastest-growing companies in New England. In 1989, they opened their first office in London. In 1993, they opened an office in Singapore, and an office in Toronto in 1994. Their corporate headquarters moved to Sudbury, Massachusetts in 1995. In 2011, Jones & Bartlett Learning moved its offices in Sudbury and Maynard, Massachusetts to Burlington, Massachusetts, sharing a building with other Ascend Learning corporate offices. See also * National Healthcareer Association * DVP Media DVP may refer to: * ''decessit vita patris'', "died in the lifetime of his father", term used by genealogists to denote a child who pre-deceased his or her father and did not live long enough to inherit the father's title or es ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Basic Books
Basic Books is a book publisher founded in 1950 and located in New York, now an imprint of Hachette Book Group. It publishes books in the fields of psychology, philosophy, economics, science, politics, sociology, current affairs, and history. History Basic Books originated as a small Greenwich Village-based book club marketed to psychoanalysts. Arthur Rosenthal took over the book club in 1950, and under his ownership it soon began producing original books, mostly in the behavioral sciences. Early successes included Ernest Jones's ''The Life and Work of Sigmund Freud'', as well as works by Claude Lévi-Strauss, Jean Piaget and Erik Erikson. Irving Kristol joined Basic Books in 1960, and helped Basic to expand into the social sciences. Harper & Row purchased the company in 1969. In 1997, HarperCollins announced that it would merge Basic Books into its trade publishing program, effectively closing the imprint and ending its publishing of serious academic books. That same year, Bas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of California At Santa Cruz
The University of California, Santa Cruz (UC Santa Cruz or UCSC) is a public land-grant research university in Santa Cruz, California. It is one of the ten campuses in the University of California system. Located on Monterey Bay, on the edge of the coastal community of Santa Cruz, the campus lies on of rolling, forested hills overlooking the Pacific Ocean. Founded in 1965, UC Santa Cruz began with the intention to showcase progressive, cross-disciplinary undergraduate education, innovative teaching methods and contemporary architecture. The residential college system consists of ten small colleges that were established as a variation of the Oxbridge collegiate university system. Among the Faculty is 1 Nobel Prize Laureate, 1 Breakthrough Prize in Life Sciences recipient, 12 members from the National Academy of Sciences, 28 members of the American Academy of Arts and Sciences, and 40 members of the American Association for the Advancement of Science. Eight UC Santa Cruz alumni ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anisotropy
Anisotropy () is the property of a material which allows it to change or assume different properties in different directions, as opposed to isotropy. It can be defined as a difference, when measured along different axes, in a material's physical or mechanical properties (absorbance, refractive index, conductivity, tensile strength, etc.). An example of anisotropy is light coming through a polarizer. Another is wood, which is easier to split along its grain than across it. Fields of interest Computer graphics In the field of computer graphics, an anisotropic surface changes in appearance as it rotates about its geometric normal, as is the case with velvet. Anisotropic filtering (AF) is a method of enhancing the image quality of textures on surfaces that are far away and steeply angled with respect to the point of view. Older techniques, such as bilinear and trilinear filtering, do not take into account the angle a surface is viewed from, which can result in aliasing or bl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hubble's Law
Hubble's law, also known as the Hubble–Lemaître law, is the observation in physical cosmology that galaxies are moving away from Earth at speeds proportional to their distance. In other words, the farther they are, the faster they are moving away from Earth. The velocity of the galaxies has been determined by their redshift, a shift of the light they emit toward the red end of the visible spectrum. Hubble's law is considered the first observational basis for the expansion of the universe, and today it serves as one of the pieces of evidence most often cited in support of the Big Bang model. The motion of astronomical objects due solely to this expansion is known as the Hubble flow. It is described by the equation , with ''H''0 the constant of proportionality—the Hubble constant—between the "proper distance" ''D'' to a galaxy, which can change over time, unlike the comoving distance, and its speed of separation ''v'', i.e. the derivative of proper distance with respect ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Space Telescope Science Institute
The Space Telescope Science Institute (STScI) is the science operations center for the Hubble Space Telescope (HST), science operations and mission operations center for the James Webb Space Telescope (JWST), and science operations center for the Nancy Grace Roman Space Telescope. STScI was established in 1981 as a community-based science center that is operated for NASA by the Association of Universities for Research in Astronomy (AURA). STScI's offices are located on the Johns Hopkins University Homewood Campus and in the Rotunda building in Baltimore, Maryland. In addition to performing continuing science operations of HST and preparing for scientific exploration with JWST and Roman, STScI manages and operates the Mikulski Archive for Space Telescopes (MAST), which holds data from numerous active and legacy missions, including HST, JWST, Kepler, TESS, Gaia, and Pan-STARRS. Most of the funding for STScI activities comes from contracts with NASA's Goddard Space Flight Center b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Baltimore, Maryland
Baltimore ( , locally: or ) is the most populous city in the U.S. state of Maryland, fourth most populous city in the Mid-Atlantic, and the 30th most populous city in the United States with a population of 585,708 in 2020. Baltimore was designated an independent city by the Constitution of Maryland in 1851, and today is the most populous independent city in the United States. As of 2021, the population of the Baltimore metropolitan area was estimated to be 2,838,327, making it the 20th largest metropolitan area in the country. Baltimore is located about north northeast of Washington, D.C., making it a principal city in the Washington–Baltimore combined statistical area (CSA), the third-largest CSA in the nation, with a 2021 estimated population of 9,946,526. Prior to European colonization, the Baltimore region was used as hunting grounds by the Susquehannock Native Americans, who were primarily settled further northwest than where the city was later built. Colonis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
