The Brightest Explosions in the Universe
Gamma-rays have the smallest wavelengths and the most energy of any other wave in the electromagnetic spectrum. These waves are generated by radioactive atoms and in nuclear explosions. Gamma-rays travel to us across vast distances of the universe, only to be absorbed by the Earth's atmosphere. Different wavelengths of light penetrate the Earth's atmosphere to different depths. Instruments aboard high-altitude balloons and satellites like the Compton Observatory provide our only view of the gamma-ray sky. Gamma rays are the most energetic form of light and are produced by the hottest regions of the universe. They are also produced by such violent events as supernova explosions or the destruction of atoms, and by less dramatic events, such as the decay of radioactive material in space. Things like supernova explosions (the way massive stars die), neutron stars and pulsars, and black holes are all sources of celestial gamma rays. Gamma ray bursts of GRB fall into one of two categories. Less than two seconds: short, and longer than two seconds: long. They occur isotropically, they are spread evenly over the entire sky. This contradicts the existing per
Simulations show that the central core of such a star eventually collapses to form a fast rotating black hole with material around it. Stars with masses more than 20 solar masses may be destined to become black holes providing a natural explanation for gamma-ray bursts that are later observed by groups like that of the Burst and Transient Source Experiment (BATSE). Two families of models explain what generates the energy to begin with. An interesting discovery has been the connection between GRBs and supernovae by the detection of iron in the x-ray spectra of several bursts. Unluckily, this alone did not supply sufficient information to settle for sure. The fireball then converts some of its energy into electromagnetic radiation, producing gamma ray bursts. If they are unable to break out the paradox lies on how we are able to see them. Iron atoms are known to be synthesized and dumped into interstellar space by supernova explosions. The observer sees a burst of gamma rays that lasts only a few seconds, even if it took a day to produce. This fireball expands and the photon density drops enough for the gamma rays to escape unconstrained. As the hydrogen in its core runs out it contracts and fuses heavier elements. The result of no useful fuel is a sudden catastrophic collapse. The initial gamma ray emission is most likely the result of internal shock waves within the expanding fireball expanding close to the speed of light. A massive star blows up fairly soon after it is born, so its deathbed is close to its birthplace.
Common topics in this essay:
Compton Observatory,
Experiment BATSE,
,
gamma ray,
gamma rays,
gamma ray bursts,
supernova explosions,
black holes,
ray bursts,
neutron star,
close speed light,
connection grbs supernovae,
space supernova explosions,
fuses heavier,
fuses heavier elements,
neutron stars,
earth's atmosphere,
star formation,
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