“neutron star”的概念、定义、翻译、参考文献-科学参考

neutron star

Physics

A compact stellar object that is supported against collapse under self-gravity by the degeneracy pressure of the neutrons of which it is primarily composed. Neutron stars are believed to be formed as the end products of the evolution of stars of mass greater than a few (4–10) solar masses. The core of the evolved star collapses and (assuming that its mass is greater than the Chandrasekhar limit for a white dwarf), at the very high densities involved (about 10¹⁴ kg m⁻³), electrons react with protons in atomic nuclei to produce neutrons. The neutron-rich nuclei thus formed release free neutrons in a process known as neutron drip. The density increases to about 10¹⁷ kg m⁻³, at which most of the electrons and protons have been converted to a degenerate gas of neutrons and the atomic nuclei have lost their separate identities. If the mass of the core exceeds the Oppenheimer–Volkoff limit, then further collapse will occur, leading to the formation of a black hole.

Pulsars are believed to be rapidly rotating magnetized neutron stars and many X-ray sources are thought to be neutron stars in binary systems with another star, from which material is drawn into an accretion disc. This material, heated to a very high temperature, emits radiation in the X-ray region.

Astronomy

An extremely small, superdense object believed to be formed when a massive star undergoes a Type II supernova explosion. During the explosion, the core of the massive star collapses under its own gravity until, at a density of about 10¹⁷ kg/m³, electrons and protons are so closely packed that they combine to form neutrons. The resultant object, consisting only of neutrons, is supported against further gravitational collapse by the degeneracy pressure of the neutrons, provided its mass is not greater than about 2 solar masses (the Oppenheimer–Volkoff limit). If the object were more massive it would collapse further into a black hole. A typical neutron star, with a mass a little greater than the Sun’s, would have a diameter of only about 30 km, and a density such that the mass of the entire human race would occupy the volume of a sugar cube. The greater the mass of a neutron star, the smaller its diameter. Neutron stars are believed to have an interior of superfluid neutrons (i.e. neutrons behaving like a fluid of zero viscosity), surrounded by a solid crust about 1 km thick composed of elements such as iron. Pulsars are spinning, magnetized neutron stars. Massive X-ray binaries are also thought to contain neutron stars.

Space Exploration

A very small, ‘superdense’ star composed mostly of neutrons. They are thought to form when massive stars explode as supernovae, during which the protons and electrons of the star's atoms merge, owing to intense gravitational collapse, to make neutrons. A neutron star has a mass two to three times that of the Sun, compressed into a globe only 20 km in diameter.
If its mass is any greater, its gravity will be so strong that it will shrink even further to become a black hole. Being so small, neutron stars can spin very quickly. The rapidly flashing radio stars called pulsars are believed to be neutron stars. The flashing is caused by a rotating beam of radio energy similar in behaviour to a lighthouse beam.

单词	neutron star
释义	neutron star Physics A compact stellar object that is supported against collapse under self-gravity by the degeneracy pressure of the neutrons of which it is primarily composed. Neutron stars are believed to be formed as the end products of the evolution of stars of mass greater than a few (4–10) solar masses. The core of the evolved star collapses and (assuming that its mass is greater than the Chandrasekhar limit for a white dwarf), at the very high densities involved (about 10¹⁴ kg m⁻³), electrons react with protons in atomic nuclei to produce neutrons. The neutron-rich nuclei thus formed release free neutrons in a process known as neutron drip. The density increases to about 10¹⁷ kg m⁻³, at which most of the electrons and protons have been converted to a degenerate gas of neutrons and the atomic nuclei have lost their separate identities. If the mass of the core exceeds the Oppenheimer–Volkoff limit, then further collapse will occur, leading to the formation of a black hole. Pulsars are believed to be rapidly rotating magnetized neutron stars and many X-ray sources are thought to be neutron stars in binary systems with another star, from which material is drawn into an accretion disc. This material, heated to a very high temperature, emits radiation in the X-ray region. Astronomy An extremely small, superdense object believed to be formed when a massive star undergoes a Type II supernova explosion. During the explosion, the core of the massive star collapses under its own gravity until, at a density of about 10¹⁷ kg/m³, electrons and protons are so closely packed that they combine to form neutrons. The resultant object, consisting only of neutrons, is supported against further gravitational collapse by the degeneracy pressure of the neutrons, provided its mass is not greater than about 2 solar masses (the Oppenheimer–Volkoff limit). If the object were more massive it would collapse further into a black hole. A typical neutron star, with a mass a little greater than the Sun’s, would have a diameter of only about 30 km, and a density such that the mass of the entire human race would occupy the volume of a sugar cube. The greater the mass of a neutron star, the smaller its diameter. Neutron stars are believed to have an interior of superfluid neutrons (i.e. neutrons behaving like a fluid of zero viscosity), surrounded by a solid crust about 1 km thick composed of elements such as iron. Pulsars are spinning, magnetized neutron stars. Massive X-ray binaries are also thought to contain neutron stars. Space Exploration A very small, ‘superdense’ star composed mostly of neutrons. They are thought to form when massive stars explode as supernovae, during which the protons and electrons of the star's atoms merge, owing to intense gravitational collapse, to make neutrons. A neutron star has a mass two to three times that of the Sun, compressed into a globe only 20 km in diameter. If its mass is any greater, its gravity will be so strong that it will shrink even further to become a black hole. Being so small, neutron stars can spin very quickly. The rapidly flashing radio stars called pulsars are believed to be neutron stars. The flashing is caused by a rotating beam of radio energy similar in behaviour to a lighthouse beam.
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