Содержание
- 2. Skeleton Why space astronomy? Atmospheric windows and distortion Visible range. Atmospheric seeing and transmissivity. Objects and
- 3. Why space astronomy? The atmosphere filters and distorts the incoming light: Some parts of the EM
- 5. Atmospheric windows
- 13. Visible
- 14. Atmospheric distortion due to turbulence. To a higher or lesser extent, this distortion (seeing) is always
- 16. CCD cameras Charge Coupled Devices are based on the photoelectric effect. Resulting electrons are stored in
- 18. CCD cameras. Pre-processing
- 19. Flat field: Caused by inhomogeneity in the illumination Sources: dust, defects on the CCD chip, contamination
- 20. Dark field: Caused by thermal noise. The longer the exposure, the higher the electron counts. Extra
- 23. Quantum efficiency: fraction of detected photons as a function of wavelength
- 24. Filters CCD cameras are monochromatic. To obtain colour information, there are sets of standard filters.
- 26. Adaptive optics Adaptive optics are a family of methods to improve the resolution of ground based
- 28. Adaptive optics allow a significant reduction of distortion at the cost of an increase in complexity
- 29. Gaia – ESA cornerstone mission L1 Gaia is gathering information (position, parallax, brightness, and spectra) of
- 34. Map of the sky generated with Gaia’s DR2 (includes 1.7 billion objects) Gaia DR2
- 35. Catalogues for Star Trackers So far, the catalogues used for star trackers have included a few
- 38. Often, there is a prior on the pointing that allows a very significant reduction on the
- 39. The James Webb Space Telescope It is the successor of the Hubble Space Telescope The diameter
- 44. Silly ideas also have an effect on Astronomy
- 45. Ultraviolet
- 46. Infrared
- 47. Infrared telescopes
- 48. There are several windows in the IR, and so observations can be made from the ground
- 49. IRAS all-sky map
- 51. ISO (2.5 – 240 μm)
- 52. Infrared detectors The CCDs we have analysed for visible range have a fair QE in the
- 53. Radio
- 54. X rays
- 55. The Crab Nebula as imaged by ROSAT (left) and Chandra (right). Credit: S. L. Snowden USRA,
- 56. The Cygnus Loop Supernova Remnant in X-rays as imaged by three different X-ray telescopes. From the
- 57. X-ray telescopes X rays are capable of penetrating matter, and thus are not efficiently reflected by
- 58. X-ray reflectance
- 59. X-ray reflectance
- 61. This system generates an annular aperture. In the case of Chandra, the external paraboloid had a
- 62. Solution: co-aligned, confocal, nested mirrors
- 63. XMM Newton
- 65. Wolter type I telescope (NASA) Einstein ROSAT Chandra XMM
- 66. Wolter type II telescope (NASA) EUVE
- 67. Wolter type III telescope (NASA)
- 68. CCDs for X-rays Semiconductors release electrons when an X-ray photon impacts on them The number of
- 69. Gas proportional counters In this kind of detectors, a gas is ionized by incoming X-ray photons
- 70. If the geometry of the detector and the radius of the wire are adequate, the number
- 71. Scintillators When an X-ray photon is absorbed by the matter of the detector, produces a visible
- 72. Microcalorimeters These devices measure the heat deposited by a single X-ray photon on the detector To
- 73. Gamma rays
- 74. Fermi LAT gamma ray sky at 1 GeV
- 76. Physical processes and detectors Gamma rays are produced in nuclear processes (X-rays are generated in electronic
- 77. Compton effect detectors Compton effect accounts for the scattering of high energy photons by charged particles.
- 78. Compton effect detectors Compton effect telescopes scatter the incoming photon on a scintillator, and absorb it
- 79. Pair telescopes Useful for gamma ray imaging at energies over 30 MeV
- 80. Gravitational wave astronomy
- 81. Wrinkles in space time Violent events involving large masses generate gravitational waves that are within our
- 82. LISA – Pathfinder LISA is one of ESA’s cornerstone mission LISA – Pathfinder is a technological
- 84. One of the sources of noise was the residual gas impacting on the cubes
- 86. Just something to keep in mind
- 87. Asteroid 2015 bz509: an interstellar object in solar orbit
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