Bibcode
Green, P. J.; Aldcroft, T. A.; Garcia, M. R.; Slane, P.; Vrtilek, J.
Bibliographical reference
Proceedings of the ESA Symposium `Hipparcos - Venice '97', 13-16 May, Venice, Italy, ESA SP-402 (July 1997), p. 187-190
Advertised on:
8
1997
Citations
1
Refereed citations
1
Description
AXAF, the Advanced X-ray Astrophysics Facility will be the third
satellite in the series of great observatories in the NASA program,
after the Hubble Space Telescope and the Gamma Ray Observatory. At
launch in fall 1998, AXAF will carry a high resolution mirror, two
imaging detectors, and two sets of transmission gratings (Holt 1993).
Important AXAF features are: an order of magnitude improvement in
spatial resolution, good sensitivity from 0.1-10keV, and the capability
for high spectral resolution observations over most of this range. The
Tycho Catalogue from the Hipparcos mission will serve as a primary part
of the AXAF Guide and Aspect Star Catalog (AGASC), particularly as
merged with other star catalogues. Incorporation of the Tycho Catalogue
into AGASC will provide: (1) accurate positions and magnitudes for
target acquisition and guiding; (2) the colours necessary for magnitude
transformations to the AXAF Aspect Camera (ACA) system; (3) high
internal astrometric accuracy for half-arcsecond post-facto image
reconstruction; and (4) an external astrometric system that will tie
AXAF X-ray image astrometry into the best positional system expected
well beyond the mission lifetime and into the next millennium.