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Phoenix Cluster
The Phoenix Cluster (SPT-CL J2344-4243) is a massive, Abell class type I galaxy cluster located at its namesake, southern constellation of Phoenix. It was initially detected in 2010 during a 2,500 square degree survey of the southern sky using the Sunyaev–Zel'dovich effect by the South Pole Telescope collaboration. It is one of the most massive galaxy clusters known, with the mass on the order of 2 , and is the most luminous X-ray cluster discovered, producing more X-rays than any other known massive cluster. It is located at a comoving distance of 8.57 billion light-years from Earth. About 42 member galaxies were identified and currently listed in the SIMBAD Astronomical Database, though the real number may be as high as 1,000. Powerful Black Hole at Heart of Phoenix Cluster’s Central Galaxy Surprises Astronomer/ref> Discovery The Phoenix Cluster has first been reported by a paper by R. Williamson and colleagues during a survey by the South Pole Telescope in Antarctica, be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cooling Flow
A cooling flow occurs according to the theory that the intracluster medium (ICM) in the centres of galaxy clusters should be rapidly cooling at the rate of tens to thousands of solar masses per year. This should happen as the ICM (a plasma) is quickly losing its energy by the emission of X-rays. The X-ray brightness of the ICM is proportional to the square of its density, which rises steeply towards the centres of many clusters. Also the temperature falls to typically a third or a half of the temperature in the outskirts of the cluster. The typical redictedtimescale for the ICM to cool is relatively short, less than a billion years. As material in the centre of the cluster ''cools out'', the pressure of the overlying ICM should cause more material to flow inwards (the cooling flow). In a steady state, the rate of ''mass deposition'', i.e. the rate at which the plasma cools, is given by : \dot = \frac \frac, where ''L'' is the bolometric (i.e. over the entire spectrum) luminosity o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
R&D Magazine
Advantage Business Marketing (ABM) was a private American digital marketing and information services company owned by the venture capital firm Owner Resource Group. The company was founded in 2006 and was based in Rockaway, New Jersey, United States. It filed for bankruptcy in June 2019. Business model In the period between 2006 and 2014, the company transitioned from print-centric to digital media, increasing digital revenues from 11% to 50% of total revenues. The company's growth during this period came from both "organic" growth and strategic acquisitions. In 2018, the organization transitioned fully from a digital media organization to a digital marketing organization, following market trends. As such, the company changed its name from Advantage Business Media to Advantage Business Marketing, updated its logo, and began the overhaul of its digital websites and assets. The organization offered digital marketing services including inbound marketing, branding, automation serv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NGC 1275
NGC 1275 (also known as Perseus A or Caldwell 24) is a type 1.5 Seyfert galaxy located around 237 million light-years away in the direction of the constellation Perseus. NGC 1275 corresponds to the radio galaxy Perseus A and is situated near the center of the large Perseus Cluster of galaxies. Properties NGC 1275 consists of two galaxies, a central type-cD galaxy in the Perseus Cluster, and a so-called "high velocity system" (HVS) which lies in front of it. The HVS is moving at 3000 km/s towards the dominant system, and is believed to be merging with the Perseus Cluster. The HVS is not affecting the cD galaxy as it lies at least 200 thousand light years from it. However tidal interactions are disrupting it and ram-pressure stripping produced by its interaction with the intracluster medium of Perseus is stripping its gas as well as producing large amounts of star formation within it The central cluster galaxy contains a massive network of spectral line emitting filame ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Herschel Space Observatory
The Herschel Space Observatory was a space observatory built and operated by the European Space Agency (ESA). It was active from 2009 to 2013, and was the largest infrared telescope ever launched until the launch of the James Webb Space Telescope in 2021. Herschel carries a mirror and instruments sensitive to the far infrared and submillimetre wavebands (55–672 µm). Herschel was the fourth and final cornerstone mission in the Horizon 2000 programme, following ''SOHO''/'' Cluster II'', ''XMM-Newton'' and ''Rosetta''. The observatory was carried into orbit by an Ariane 5 in May 2009, reaching the second Lagrangian point (L2) of the Earth–Sun system, from Earth, about two months later. Herschel is named after Sir William Herschel, the discoverer of the infrared spectrum and planet Uranus, and his sister and collaborator Caroline Herschel. The observatory was capable of seeing the coldest and dustiest objects in space; for example, cool cocoons where stars form and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GALEX
Galaxy Evolution Explorer (GALEX or Explorer 83 or SMEX-7) was a NASA orbiting space telescope designed to observe the universe in ultraviolet wavelengths to measure the history of star formation in the universe. In addition to paving the way for future ultraviolet missions, the space telescope allowed astronomers to uncover mysteries about the early universe and how it evolved, as well as better characterize phenomena like black holes and dark matter. The mission was extended three times over a period of 10 years before it was decommissioned in June 2013. GALEX was launched on 28 April 2003 and decommissioned in June 2013. Spacecraft The spacecraft was three-axis stabilized, with power coming from four fixed solar panels. The satellite bus is from Orbital Sciences Corporation based on OrbView 4. The telescope was a Modified Ritchey–Chrétien with a rotating grism. GALEX used the first ever UV light dichroic beam-splitter flown in space to direct photons to the Nea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Baby Boom Galaxy
The Baby Boom Galaxy is a starburst galaxy located 12.477 billion light years away (co-moving distance is 25.08 billion light years). Discovered by NASA's Spitzer Science Center at the California Institute of Technology, the galaxy is the record holder for the brightest starburst galaxy in the very distant universe, with brightness being a measure of its extreme star-formation rate. The Baby Boom Galaxy has been nicknamed "the extreme stellar machine" because it is seen producing stars at a rate of up to 4,000 per year (almost 11 stars per day). The Milky Way galaxy in which Earth resides turns out an average of just 10 stars per year. Discovery The Baby Boom Galaxy was discovered and characterized in 2008 using a suite of telescopes operating at different wavelengths. NASA's Hubble Space Telescope and Japan's Subaru Telescope, atop Mauna Kea in Hawaii, first spotted the galaxy in visible-light images, where it appeared as an inconspicuous smudge due to its great distance. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Supermassive Black Hole
A supermassive black hole (SMBH or sometimes SBH) is the largest type of black hole, with its mass being on the order of hundreds of thousands, or millions to billions of times the mass of the Sun (). Black holes are a class of astronomical objects that have undergone gravitational collapse, leaving behind spheroidal regions of space from which nothing can escape, not even light. Observational evidence indicates that almost every large galaxy has a supermassive black hole at its Central massive object, center. For example, the Milky Way has a Galactic Center#Supermassive black hole, supermassive black hole in its Galactic Center, corresponding to the Astronomical radio source, radio source Sagittarius A*. Accretion (astrophysics), Accretion of Interstellar medium, interstellar gas onto supermassive black holes is the process responsible for powering Active galactic nucleus, active galactic nuclei (AGNs) and quasars. Two supermassive black holes have been directly imaged by the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seyfert Galaxy
Seyfert galaxies are one of the two largest groups of active galaxies, along with quasars. They have quasar-like nuclei (very luminous, distant and bright sources of electromagnetic radiation) with very high surface brightnesses whose spectra reveal strong, high-ionisation emission lines, but unlike quasars, their host galaxies are clearly detectable. Seyfert galaxies account for about 10% of all galaxies and are some of the most intensely studied objects in astronomy, as they are thought to be powered by the same phenomena that occur in quasars, although they are closer and less luminous than quasars. These galaxies have supermassive black holes at their centers which are surrounded by accretion discs of in-falling material. The accretion discs are believed to be the source of the observed ultraviolet radiation. Ultraviolet emission and absorption lines provide the best diagnostics for the composition of the surrounding material. Seen in visible light, most Seyfert galaxies ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quasar
A quasar is an extremely Luminosity, luminous active galactic nucleus (AGN). It is pronounced , and sometimes known as a quasi-stellar object, abbreviated QSO. This emission from a galaxy nucleus is powered by a supermassive black hole with a mass ranging from millions to tens of billions of solar masses, surrounded by a gaseous accretion disc. Gas in the disc falling towards the black hole heats up because of friction and releases energy in the form of electromagnetic radiation. The radiant energy of quasars is enormous; the most powerful quasars have luminosity, luminosities thousands of times greater than that of a galaxy such as the Milky Way. Usually, quasars are categorized as a subclass of the more general category of AGN. The redshifts of quasars are of Expansion of the universe, cosmological origin. The term originated as a Contraction (grammar), contraction of "quasi-stellar ''[star-like]'' radio source"—because quasars were first identified during the 1950s as sour ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Active Galactic Nucleus
An active galactic nucleus (AGN) is a compact region at the center of a galaxy that has a much-higher-than-normal luminosity over at least some portion of the electromagnetic spectrum with characteristics indicating that the luminosity is not produced by stars. Such excess non-stellar emission has been observed in the radio, microwave, infrared, optical, ultra-violet, X-ray and gamma ray wavebands. A galaxy hosting an AGN is called an "active galaxy". The non-stellar radiation from an AGN is theorized to result from the accretion of matter by a supermassive black hole at the center of its host galaxy. Active galactic nuclei are the most luminous persistent sources of electromagnetic radiation in the universe, and as such can be used as a means of discovering distant objects; their evolution as a function of cosmic time also puts constraints on models of the cosmos. The observed characteristics of an AGN depend on several properties such as the mass of the central black hole, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Type-cD Galaxy
The type-cD galaxy (also cD-type galaxy, cD galaxy) is a galaxy morphology classification, a subtype of type-D giant elliptical galaxy. Characterized by a large halo of stars, they can be found near the centres of some rich galaxy clusters. They are also known as supergiant ellipticals or central dominant galaxies. Characteristics The cD-type is a classification in the Yerkes galaxy classification scheme, one of two Yerkes classifications still in common use, along with D-type. The "c" in "cD" refers to the fact that the galaxies are very large, hence the adjective supergiant, while the "D" refers to the fact that the galaxies appear diffuse. A backformation of "cD" is frequently used to indicate "central Dominant galaxy"."Uncertainties on Clusters of Galaxies Distances", C. Adami, M.P. Ulmer, 18 July 2000, (accessed 14 April 2010) cDs are also frequently considered the largest galaxies. cD galaxies are similar to lenticular galaxies (S0) or elliptical galaxies (E#), but many ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
_Chandra.jpg "Click for more on -> Phoenix Cluster")
