Cosmic X-ray sources
نویسندگان
چکیده
منابع مشابه
Cosmic X-ray Sources
The atmosphere of the Earth is opaque to most wavelengths of light in the infrared, in the ultraviolet and in the X-rays. Due to this fact observation of celestial objects in X-rays (in the range of energies from 0.5 to 20 keV) must be carried out outside the atmosphere at altitudes greater than 100 kilometers, namely from space. The development of X-ray astronomy had therefore to await the dev...
متن کاملCosmic X-ray Sources - Ii
During the first discovery flight of ScoX-1 in 1962 an isotropic X-ray background was observed (Giacconi et al. 1962). This had immediate consequences for cosmology. Hoyle’s Hot Universe continuous creation theory could not account for this emission, and this created a major difficulty for the theory as a whole. Burbidge suggested that the emission could be due to the sum of unresolved galaxies...
متن کاملTime Delays in Cosmic Ray Propagation
Cosmic Rays (CR) travel at speeds essentially indistinguishable from the speed of light. However whilst travelling through magnetic fields, both regular and turbulent, they are delayed behind the light since they are usually charged particles and their paths are not linear. Those delays can be so long that they are an impediment to correctly identifying sources which may be variable in time. Fu...
متن کاملCosmic-ray Sources and Source Composition
Present data on cosmic-ray elemental and isotopic relative abundances are shown to be unable to distinguish between various models of cosmic-ray sources and their composition. For example, the model of freshly nucleosynthesized material from supernova explosions as the cosmic-ray source is unable to account for some measured, key cosmic-ray elemental abundances. This and two other models are ev...
متن کاملIsotopic composition of cosmic-ray sources
We use the GALPROP code and the Advanced Composition Explorer (ACE) data to derive the cosmic ray (CR) isotopic composition at the sources. The composition is derived for two propagation models, diffusive reacceleration and plain diffusion. We show that the compositions derived assuming these two propagation models are different. We also compare the isotopic composition at the sources with the ...
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ژورنال
عنوان ژورنال: Scholarpedia
سال: 2008
ISSN: 1941-6016
DOI: 10.4249/scholarpedia.4391