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ASCA: The Advanced Satellite for Cosmology and Astrophysics
he Advanced Satellite for Cosmology and
Astrophysics, ASCA, is Japan's fourth cosmic X-ray astronomy mission, and
the second for which the United States is providing part of the scientific
payload. The satellite was successfully launched on February 20, 1993.
ASCA operated successfully till July 15 2000 when it was transferred into a
safe-hold mode. The satellite re-entered on March 2, 2001 after 7 and
half
years of scientific observations. ASCA was the first satellite to use CCD
detectors for X-ray astronomy.
Mission Characteristics
Lifetime : February 20, 1993 - March 2, 2001
Energy Range : 0.4 - 10 keV
Special Features : First X-ray mission to combine
imaging capability with broad pass band, good spectral resolution, and a
large effective area
Payload :
- Four X-ray telescopes each composed of 120 nested gold-coated
aluminum foil surfaces (total eff area 1,300 cm2 @ 1
keV, spatial resolution 3´ half power diameter, FOV 24´ @
1 keV) working in conjunction with one of the following detectors:
- a Gas Imaging Spectrometer (GIS; 0.8-12 keV)
Two Imaging Gas Scintillation Proportional Counters (IGSPC)
FOV 50´,
spatial resolution ~0.5' at 5.9 keV,
and energy resolution of 8 % at 5.9 keV,
Eff area (GIS+XRT) 50 cm2 @ 1 keV
- Solid-state Imaging Spectrometer (SIS; 0.4-12 keV)
Two CCD arrays of four 420 X 422 square pixel chips,
FOV 22´ X 22´,
Spatial resolution 30",
energy resolution of 2 % at 5.9 keV ,
Eff area (SIS+XRT) 105 cm2
Science Highlight:
Archive : Catalogs, Spectra, Lightcurves, Images and Raw data
[ASCA Guest Observer Facility] (http://heasarc.gsfc.nasa.gov/docs/asca/ascagof.html)
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