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The Crab Pulsar, a neutron star 28–30 kilometres (17–19 mi) across with a spin rate of 30.2 times per second, lies at the center of the Crab Nebula. The star emits pulses of radiation from gamma rays to radio waves .
However, because of the Crab Nebula's variable intensity at different X-ray energies, conversion of the Crab to another units depends on the X-ray energy range of interest. In the photon energy range from 2 to 10 keV , 1 Crab equals 2.4 · 10 −8 erg cm −2 s −1 = 15 keV cm −2 s −1 = 2.4 · 10 −11 W m −2 .
Pulsed emission gamma-ray radiation from the Crab has recently been observed up to ≥25 GeV, [21] probably due to synchrotron emission by electrons trapped in the strong magnetic field around the pulsar. Polarization in the Crab nebula [22] at energies from 0.1 to 1.0 MeV, illustrates this typical property of synchrotron radiation.
In 1967, shortly before the discovery of pulsars, Franco Pacini suggested that a rotating neutron star with a magnetic field would emit radiation, and even noted that such energy could be pumped into a supernova remnant around a neutron star, such as the Crab Nebula. [18]
Central neutron star at the heart of the Crab Nebula Radiation from the rapidly spinning pulsar PSR B1509-58 makes nearby gas emit X-rays (gold) and illuminates the rest of the nebula, here seen in infrared (blue and red). A neutron star is the collapsed core of a massive supergiant star.
Thomas Gold has shown that the pulsar's spin-down power is sufficient to power the Crab Nebula. A subsequent study by them, including William D. Brundage, also found that the NP 0532 source is located at the Crab Nebula. [20] A radio source was also reported coincident with the Crab Nebula in late 1968 by L. I. Matveenko in Soviet Astronomy. [21]
SN 1054 remnant (Crab Nebula).. 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.
Subsequently, Sekido et al. (1951) identified the Crab Nebula as a source of cosmic rays. [51] Since then, a wide variety of potential sources for cosmic rays began to surface, including supernovae, active galactic nuclei, quasars, and gamma-ray bursts. [52] Sources of ionizing radiation in interplanetary space.