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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
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:
FileName Lrecl Records Explanations
ReadMe 80 . This file table.dat 46 181 Galaxies in the Tycho-2 Catalogue
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
Bytes Format Units Label Explanations
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)
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
Acknowledgements: M. Metz
(End) Patricia Bauer [CDS] 09-Jan-2004
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

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