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ASTROSAT Soft X-ray imaging Telescope (SXT):

Click to download SXT description paper                                                                                SXT Poster

The soft X-ray telescope on ASTROSAT will employ focussing optics and a deep depletion CCD camera at the focal plane to perform X-ray imaging in 0.3-8.0 keV band. The optics will consist of 41 concentric shells of gold-coated conical foil mirrors in an approximate Wolter-I configuration. The focal plane CCD camera will be very similar to that flown on SWIFT XRT. The CCD will be operated at a temperature of about -80oC by thermoelectric cooling.
Click to learn more about the SXT optics and the CCD camera.
The main characteristics of the SXT will be as follows:
Telescope length:
2465 mm
(including baffle, door and camera)
Focal Length: 2000 mm
Telescope PSF: 1.5 - 2.5 arcmin (rms)
Field of View: 41.3 x 41.3 arcmin
Energy range: 0.3-8.0 keV
E2V CCD-22
(Frame Store)
Detector Format: 600x600 pixels
Pixel Scale: 4.13 arc sec/pixel
CCD Readout modes: Photon Counting, Imaging, Timing
Effective Area:
200 cm2 @ 1.5 keV
(See figure below)
Position accuracy: 30 arc sec
Sensitivity expected:
10 micro Crab
or better



  Outer structure of the SXT is as shown in above figure                                                                                                         


The effective area of the SXT as a function of photon energy is displayed below: