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Radio-quiet Neutron Star
A radio-quiet neutron star is a neutron star that does not seem to emit radio emissions, but is still visible to Earth through electromagnetic radiation at other parts of the spectrum, particularly X-rays and gamma rays. Background Most detected neutron stars are pulsars, and emit radio-frequency electromagnetic radiation. About 700 radio pulsars are listed in the Princeton catalog, and all but one emit radio waves at the 400 MHz and 1400 MHz frequencies. That exception is Geminga, which is radio quiet at frequencies above 100 MHz, but is a strong emitter of X-rays and gamma rays. In all, ten bodies have been proposed as rotation-powered neutron stars that are not visible as radio sources, but are visible as X-ray and gamma ray sources. Indicators that they are indeed neutron stars include them having a high X-ray to lower frequencies emission ratio, a constant X-ray emission profile, and coincidence with a gamma ray source. Theories Quark stars, theoretical neu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neutron Star Illustrated
The neutron is a subatomic particle, symbol or , which has a neutral (not positive or negative) charge, and a mass slightly greater than that of a proton. Protons and neutrons constitute the nuclei of atoms. Since protons and neutrons behave similarly within the nucleus, and each has a mass of approximately one atomic mass unit, they are both referred to as nucleons. Their properties and interactions are described by nuclear physics. Protons and neutrons are not elementary particles; each is composed of three quarks. The chemical properties of an atom are mostly determined by the configuration of electrons that orbit the atom's heavy nucleus. The electron configuration is determined by the charge of the nucleus, which is determined by the number of protons, or atomic number. The number of neutrons is the neutron number. Neutrons do not affect the electron configuration, but the sum of atomic and neutron numbers is the mass of the nucleus. Atoms of a chemical element that di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Soft Gamma Repeater
A soft gamma repeater (SGR) is an astronomical object which emits large bursts of gamma-rays and X-rays at irregular intervals. It is conjectured that they are a type of magnetar or, alternatively, neutron stars with fossil disks around them. History On March 5, 1979 a powerful gamma-ray burst was noted. As a number of receivers at different locations in the Solar System saw the burst at slightly different times, its direction could be determined, and it was shown to originate from near a supernova remnant in the Large Magellanic Cloud. Over time it became clear that this was not a normal gamma-ray burst. The photons were less energetic in the soft gamma-ray and hard X-ray range, and repeated bursts came from the same region. Astronomer Chryssa Kouveliotou of the Universities Space Research Association (USRA) at NASA's Marshall Space Flight Center decided to test the theory that soft gamma repeaters were magnetars. According to the theory, the bursts would cause the object to sl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IRAS 00500+6713
IRAS 00500+6713 is a type of star announced in December 2020 and created by the explosive merger of two ultra-dense white dwarfs. It consists of a super-hot central star, a super-Chandrasekhar object with a mass ≳1.5 M⊙ called J005311, surrounded by a nebula packed with hot gas and warm dust. The star represents a new kind of X-ray source. It exhibits record-breaking wind speeds and large amounts of neon, magnesium, silicon, and sulfur. It has been linked to the supernova SN 1181. The star is highly unstable, too massive to remain as a white dwarf, and it is predicted to collapse into a neutron star A neutron star is the collapsed core of a massive supergiant star, which had a total mass of between 10 and 25 solar masses, possibly more if the star was especially metal-rich. Except for black holes and some hypothetical objects (e.g. white ... within ten thousand years. References Compact stars Cassiopeia (constellation) IRAS catalogue objects {{star ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rotating Radio Transient
Rotating radio transients (RRATs) are sources of short, moderately bright, radio pulses, which were first discovered in 2006. RRATs are thought to be pulsars, i.e. rotating magnetised neutron stars which emit more sporadically and/or with higher pulse-to-pulse variability than the bulk of the known pulsars. The working definition of what a RRAT is, is a pulsar which is more easily discoverable in a search for bright single pulses, as opposed to in Fourier domain searches so that 'RRAT' is little more than a label (of how they are discovered) and does not represent a distinct class of objects from pulsars. over 100 have been reported. General characteristics Pulses from RRATs are short in duration, lasting from a few milliseconds. The pulses are comparable to the brightest single pulses observed from pulsars with flux densities of a few Jansky at 1.4 GHz. Andrew Lyne, a radio astronomer involved in the discovery of RRATs, "guesses that there are only a few dozen brighter radio sourc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neutron Star Merger
A neutron star merger is a type of stellar collision. It occurs in a fashion similar to the rare brand of type Ia supernovae resulting from merging white dwarf stars. When two neutron stars orbit each other closely, they gradually spiral inward due to gravitational radiation. When the two neutron stars meet, their merger leads to the formation of either a more massive neutron star, or a black hole (depending on whether the mass of the remnant exceeds the Tolman–Oppenheimer–Volkoff limit). The merger can also create a magnetic field that is trillions of times stronger than that of Earth in a matter of one or two milliseconds. These events are believed to create short gamma-ray bursts. The merger of binary neutron stars is believed to be the origin of most elements with large atomic weights - the r-process elements. The mergers are also believed to produce kilonovae, which are transient sources of fairly isotropic longer wave electromagnetic radiation due to the radio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IGR J11014-6103
IGR may refer to: * Iguazu International Airport serving Puerto Iguazú and the nearby falls * IGR Iwate Ginga Railway in Iwate Prefecture, Japan * Imperial Japanese Government Railways (or, domestically, Imperial Government Railways) of early 20th century Japan * Indiana Guard Reserve, the state defense force of Indiana * International Gay Rugby * Insect growth regulator, a chemical that disrupts the growth and/or development of insects * The Interessengemeinschaft für Rundfunkschutzrechte (IGR), a broadcasting "IP" rights interest group ** IGR Stereo, a German standard for analogue TV stereo audio transmission claimed by the above organization. * Intergenic region * Integral Gamma-Ray source, a catalog based on observations by the INTEGRAL In mathematics Mathematics is an area of knowledge that includes the topics of numbers, formulas and related structures, shapes and the spaces in which they are contained, and quantities and their changes. These topics are represe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PKS 1209-51/52
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PKS may refer to: * Pammal K. Sambandam, a 2002 Tamil language comedy film * Państwowa Komunikacja Samochodowa, Polish transport organization * Parkstone railway station, station code * Phi Kappa Sigma International Fraternity * Parkes Catalogue of Radio Sources, an astronomical catalogue * Polyketide synthases, enzymes * Prosperous Justice Party (''Partai Keadilan Sejahtera''), Indonesia * Serbian Chamber of Commerce The Chamber of Commerce and Industry of Serbia (abbr. CCIS or PKS) is independent, modern and responsible non-budget institution, the national association of all Serbian businesses which its tradition, experience, and knowledge put in the best int ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1E 1207
1E is a privately owned IT software and services company based in the United Kingdom. 1E is headquartered in London, with offices in New York City, Dublin, and Noida. History 1E was founded in 1997 by three former Microsoft contractors, Sumir Karayi, Phil Wilcock, and Mark Blackburn, who each contributed £500 to start the company. Karayi is now the CEO, Blackburn is the CIO, whilst Wilcock has left the company. The company has more than 30 million licenses deployed worldwide, across 1,700 organizations from public and private sectors in 42 countries.[citation needed'] The company's name is derived from a computer error. When some Microsoft Windows computers crash, a blue screen containing "STOP 0x0000001E" appears. This name was chosen because the founders had the ambition that 1E could prevent this from happening to big companies. Research In 2009 1E and the Alliance to Save Energy The Alliance to Save Energy is a bipartisan, nonprofit coalition of business, governmen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Puppis A
Puppis A (Pup A) is a supernova remnant (SNR) about 100 light-years in diameter and roughly 6500–7000 light-years distant. Its apparent angular diameter is about 1 degree. The light of the supernova explosion reached Earth approximately 3700 years ago. Although it overlaps the Vela Supernova Remnant, it is four times more distant. A hypervelocity neutron star known as the Cosmic Cannonball has been found in this SNR. Puppis X-1 Puppis X-1 (Puppis A) was discovered by a Skylark flight in October 1971, viewed for 1 min with an accuracy ≥ 2 arcsec, probably at 1M 0821-426, with Puppis A ( RA 08h 23m 08.16s Dec -42° 41′ 41.40″) as the likely visual counterpart. Puppis A is one of the brightest X-ray sources in the X-ray sky. Its X-ray designation is 2U 0821-42. Gallery Image:PIA18468-SuperNova-PuppisA-XRayIR-20140821.jpg, Puppis A: X-ray lue:0.3-8 keV+ IR ed-green:24-70 microns(21 August 2014). Image:SuperNova-PuppisA-XRay-20140910.jpg, Puppis A: X-ray lue:high ree ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Supernova Remnant
A supernova remnant (SNR) is the structure resulting from the explosion of a star in a supernova. The supernova remnant is bounded by an expanding shock wave, and consists of ejected material expanding from the explosion, and the interstellar material it sweeps up and shocks along the way. There are two common routes to a supernova: either a massive star may run out of fuel, ceasing to generate fusion energy in its core, and collapsing inward under the force of its own gravity to form a neutron star or a black hole; or a white dwarf star may accrete material from a companion star until it reaches a critical mass and undergoes a thermonuclear explosion. In either case, the resulting supernova explosion expels much or all of the stellar material with velocities as much as 10% the speed of light (or approximately 30,000 km/s). These speeds are highly supersonic, so a strong shock wave forms ahead of the ejecta. That heats the upstream plasma up to temperatures well above mi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
