J/A+A/413/771 Galaxies in the Tycho-2 catalogue (Metz+, 2004)
Formalism and quality of a proper motion link with extragalactic objects for
astrometric satellite missions.
Metz M., Geffert M.
<Astron. Astrophys. 413, 771 (2004)>
=2004A&A...413..771M 2004A&A...413..771M
ADC_Keywords: Positional data ; Galaxies, optical
Keywords: astrometry - reference systems - quasars
Abstract:
The accuracy of the link of the proper motion system of astrometric
satellite missions like AMEX and GAIA is discussed. Monte-Carlo
methods were used to simulate catalogues of positions and proper
motions of quasars and galaxies to test the link. The main conclusion
is, that future satellite missions like GAIA may be "self-calibrated"
by their measurements of QSOs, while additional measurements from
radio stars or HST-data are needed to calibrate the less deep reaching
astrometric satellite missions of AMEX type.
Description:
We have identified galaxies in the Tycho-2 Catalogue (Cat. I/259) by
a position cross correlation with galaxy catalogues. In the table we
give the cross references to the PGC (Cat. VII/119) and the Tycho-2
positions of the galaxies.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table.dat 46 181 Galaxies in the Tycho-2 Catalogue
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See also:
I/259 : The Tycho-2 Catalogue (Hog+ 2000)
VII/119 : Catalogue of Principal Galaxies (PGC) (Paturel+ 1989)
Byte-by-byte Description of file: table.dat
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Bytes Format Units Label Explanations
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1- 4 I4 --- TYC1 The Tycho-2 Identifier, TYC1
6- 10 I5 --- TYC2 The Tycho-2 Identifier, TYC2
12 I1 --- TYC3 The Tycho-2 Identifier, TYC3
14- 18 I5 --- PGC The PGC number (VII/119)
20- 31 F12.8 deg RAdeg Tycho-2 Right ascension, ICRS (1)
33- 44 F12.8 deg DEdeg Tycho-2 Declination, ICRS (1)
46 A1 --- Class [GUS] Classification (2)
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Note (1): Data from the Tycho-2 (I/259) catalogue,
for G,U the fields Observed RA, DE, bytes 153-177 (epoch between
1990.7 and 1992.3), for S the bytes 16-40 from the file suppl_1.dat
(epoch=J1991.25).
For details see the Tycho-2 catalogue description.
Note (2): Classification:
'G' = Galaxies in the Tycho-2 Catalogue
'U' = Uncertain galaxies in the Tycho-2 Catalogue
'S' = Galaxies in the Tycho-2 Supplement 1
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Acknowledgements: M. Metz
(End) Patricia Bauer [CDS] 09-Jan-2004