Ultra Violet Imaging Telescope on ASTROSAT Satellite mission is a suite of Far Ultra Violet (FUV; 130 - 180 nm), Near Ultra Violet (NUV; 200 - 300 nm) and Visible band (VIS; 320-550nm) imagers. ASTROSAT is a first multi wavelength mission of INDIA. UVIT will image the selected regions of the sky simultaneously in three channels & observe young stars, galaxies, bright UV Sources. FOV in each of the 3 channels is ~ 28 arc-minute. Targeted angular resolution in the resulting UV images is better than 1.8 arc-second (better than 2.0 arc-second for the visible channel). Two identical co-aligned telescopes (T1, T2) of Ritchey-Chretien configuration (Primary mirror of ~375 mm diameter) collect the celestial radiation and feed to the detector system via a selectable filter on a filter wheel mechanism; gratings are available in the filter wheels of FUV and NUV channels for slit-less low resolution spectroscopy. The detector system for each of the 3 channels is generically identical. One telescope images in the FUV channel, and other images in NUV and VIS channels. One time open-able mechanical cover on each telescope also works as Sun-shield after deployment. We will present the optical tests and calibrations done on the two telescopes. Results on vibrations test and thermo-vacuum tests on the engineering model will also be presented.
Space Telescopes and Instrumentation 2012: Ultraviolet to Gamma Ray
- Pub Date:
- September 2012
- Astrophysics - Instrumentation and Methods for Astrophysics
- 9 pages, 7 figures, to be published in Proc. SPIE 8443, "Space Telescopes and Instrumentation 2012: Ultraviolet to Gamma Ray"