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Gamma-ray Burst Precursor
A gamma-ray precursor is a short X-ray outburst event that comes before the main outburst of the gamma-ray burst In gamma-ray astronomy, gamma-ray bursts (GRBs) are extremely energetic events occurring in distant Galaxy, galaxies which represent the brightest and most powerful class of explosion in the universe. These extreme Electromagnetic radiation, ele ... progenitor. There is no consensus on the mechanism for this event, although several theories have been suggested. History The first gamma-ray precursor event was from GRB 900126, a long GRB. Immediately, because of the non-thermal nature of the emission, it was recognized that the mechanism of emission for this event was likely internal to the neutron star and not from the accretion disk. Systematic surveys were subsequently carried out to find the percentages of gamma-ray bursts that contained precursor events. Although it was found that 3% of bursts in the BATSE catalogue had a precursor event, a later review found t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
X-ray
An X-ray (also known in many languages as Röntgen radiation) is a form of high-energy electromagnetic radiation with a wavelength shorter than those of ultraviolet rays and longer than those of gamma rays. Roughly, X-rays have a wavelength ranging from 10 Nanometre, nanometers to 10 Picometre, picometers, corresponding to frequency, frequencies in the range of 30 Hertz, petahertz to 30 Hertz, exahertz ( to ) and photon energies in the range of 100 electronvolt, eV to 100 keV, respectively. X-rays were discovered in 1895 in science, 1895 by the German scientist Wilhelm Röntgen, Wilhelm Conrad Röntgen, who named it ''X-radiation'' to signify an unknown type of radiation.Novelline, Robert (1997). ''Squire's Fundamentals of Radiology''. Harvard University Press. 5th edition. . X-rays can penetrate many solid substances such as construction materials and living tissue, so X-ray radiography is widely used in medical diagnostics (e.g., checking for Bo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gamma-ray Burst
In gamma-ray astronomy, gamma-ray bursts (GRBs) are extremely energetic events occurring in distant Galaxy, galaxies which represent the brightest and most powerful class of explosion in the universe. These extreme Electromagnetic radiation, electromagnetic emissions are second only to the Big Bang as the most energetic and luminous phenomenon ever known. Gamma-ray bursts can last from a few milliseconds to several hours. After the initial flash of gamma rays, a longer-lived afterglow is emitted, usually in the longer wavelengths of X-ray, ultraviolet, visible spectrum, optical, infrared, microwave or radio waves, radio frequencies. The intense radiation of most observed GRBs is thought to be released during a supernova or superluminous supernova as a high-mass star implodes to form a neutron star or a black hole. Short-duration (sGRB) events are a subclass of GRB signals that are now known to originate from the cataclysmic Neutron star merger, merger of binary neutron stars. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Compton Gamma Ray Observatory
The Compton Gamma Ray Observatory (CGRO) was a space observatory detecting photons with photon energy, energies from 20 kElectronvolt#Properties, eV to 30 GeV, in Earth orbit from 1991 to 2000. The observatory featured four main telescopes in one spacecraft, covering X-rays and gamma rays, including various specialized sub-instruments and detectors. Following 14 years of effort, the observatory was launched from Space Shuttle Atlantis, Space Shuttle ''Atlantis'' during STS-37 on April 5, 1991, and operated until its Atmospheric entry#Deorbit disposal, deorbit on June 4, 2000. It was deployed in low Earth orbit at to avoid the Van Allen radiation belt. It was the heaviest astrophysical payload ever flown at that time at . Costing $617 million, the CGRO was part of NASA's Great Observatories program, Great Observatories series, along with the Hubble Space Telescope, the Chandra X-ray Observatory, and the Spitzer Space Telescope. It was the second of the series to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Superluminous Supernova
A superluminous supernova (SLSN, plural superluminous supernovae or SLSNe) is a type of stellar explosion with a luminosity 10 or more times higher than that of standard supernovae. Like supernovae, SLSNe seem to be produced by several mechanisms, which is readily revealed by their light-curves and spectra. There are multiple models for what conditions may produce an SLSN, including core collapse in particularly massive stars, millisecond magnetars, interaction with circumstellar material (CSM model), or pair-instability supernovae. The first confirmed superluminous supernova connected to a gamma ray burst was not found until 2003, when GRB 030329 illuminated the Leo constellation. SN 2003dh represented the death of a star 25 times more massive than the Sun, with material being blasted out at over a tenth the speed of light. Stars with are likely to produce superluminous supernovae. Classification Discoveries of many SLSNe in the 21st century showed that not only were ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gamma-ray Bursts
In gamma-ray astronomy, gamma-ray bursts (GRBs) are extremely energetic events occurring in distant galaxies which represent the brightest and most powerful class of explosion in the universe. These extreme electromagnetic emissions are second only to the Big Bang as the most energetic and luminous phenomenon ever known. Gamma-ray bursts can last from a few milliseconds to several hours. After the initial flash of gamma rays, a longer-lived afterglow is emitted, usually in the longer wavelengths of X-ray, ultraviolet, optical, infrared, microwave or radio frequencies. The intense radiation of most observed GRBs is thought to be released during a supernova or superluminous supernova as a high-mass star implodes to form a neutron star or a black hole. Short-duration (sGRB) events are a subclass of GRB signals that are now known to originate from the cataclysmic merger of binary neutron stars. The sources of most GRB are billions of light years away from Earth, implying that the e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
