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X-ray Telescopes
The XRS and the XISs would be useless without the
X-Ray
Telescopes (XRTs), like a photographic film without a camera.
The use of focusing telescopes for X-ray astronomy
started with the Einstein satellite in the late 1970s.
This made a huge improvement in our ability to see faint X-ray sources!
Galileo made a similar jump about 400 years ago, when he pointed his
telescope at the night sky. If you've ever observed the night sky
through a telescope, you know what difference it can make.
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Each of the Suzaku XRTs is made up from about 1400 conically
shaped mirrors. They are nested in about 170 layers, each taking the
form of a quadrant of a section of a cone, as shown to the right.
These foils are positioned in telescope housings. There are two stages
- each X-ray bounces off first one mirror, then another. These two stages
combined focus the X-rays at a point about 4.5 meters away. Each
telescope has a diameter of about 40 cm, and weighs approximately 20 kg.
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Watch Mr. Curtis Odell explain how the XRT works.
Click on the image above to view the QuickTime video. (1.9 MB) (Description)
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The XRTs on Suzaku have been developed by a collaboration of GSFC,
ISAS, and University of Nagoya. Dr. Peter Serlemitsos of GSFC invented
the design for these lightweight X-ray telescopes. He and his colleagues
have built this type of X-ray telescopes for BBXRT (a NASA Shuttle mission)
and for ASCA (the previous Japanese X-ray astronomy satellite).
The XRTs are designed for the biggest size per weight. But this meant
they can't quite achieve the ideal shape for an X-ray telescope. So
the images produced by Suzaku XRTs are not as sharp and
well focused as those produced by the Chandra X-ray Observatory.
No matter. The Suzaku XRTs are much cheaper and lighter,
which is important when you have to launch them into orbit! Also, they
can collect higher energy X-ray photons better, particularly in the
4 to 10 keV range.
For more information, see
http://astrophysics.gsfc.nasa.gov/xrays/MirrorLab/xrt.html
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