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Handbook of X-ray astronomy /
"It may be obvious why visible astronomy utilizes images, but it is illustrative to consider the value of focusing to X-ray astronomy. A list of advantages offered by the best possible two-dimensional angular resolution would include: (i) Resolving sources with small angular separation and dist...
| Clasificación: | Libro Electrónico |
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| Otros Autores: | , , |
| Formato: | Electrónico eBook |
| Idioma: | Inglés |
| Publicado: |
Cambridge, UK ; New York :
Cambridge University Press,
2011.
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| Colección: | Cambridge observing handbooks for research astronomers.
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| Temas: | |
| Acceso en línea: | Texto completo |
| Sumario: | "It may be obvious why visible astronomy utilizes images, but it is illustrative to consider the value of focusing to X-ray astronomy. A list of advantages offered by the best possible two-dimensional angular resolution would include: (i) Resolving sources with small angular separation and distinguishing different regions of the same source. (ii) Using the image morphology to apply intuition in choosing specific models for quantitative fits to the data. (iii) Using as a "collector" to gather photons. This is necessary because X-ray-source fluxes are so low that individual X-ray photons are detected; the weakest sources give less than one photon per day. (iv) Using as a "concentrator," so that the photons from individual sources interact in such a small region of the detector that residual non-X-ray background counts are negligible. (v) Measuring sources of interest and simultaneously determining the contaminating background using other regions of the detector. (vi) Using with dispersive spectrometers such as transmission or reflection gratings to provide high spectral resolution. The Earth's atmosphere completely absorbs cosmic X-rays. Consequently, X-ray observatories must be launched into space; so size, weight, and cost are always important constraints on the design. In practice this leads to a trade-off between the best possible angular resolution and the largest possible collecting area. Realizing an X-ray telescope involves two key issues: reflection of X-rays, and formation of an image"-- |
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| Descripción Física: | 1 online resource (viii, 197 pages) : illustrations |
| Bibliografía: | Includes bibliographical references (pages 190-194) and index. |
| ISBN: | 9781139157087 1139157086 9781139160896 1139160893 9781139034234 1139034235 128334095X 9781283340953 9781139158848 1139158848 1107226082 9781107226081 1139159895 9781139159890 9786613340955 6613340952 1139155334 9781139155335 |