PPM-Extended (PPMX) - a catalogue of positions and proper motions
| Autor: | Roeser, S., Schilbach, E., Schwan, H., Kharchenko, N. V., Piskunov, A. E., Scholz, R. -D. |
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| Rok vydání: | 2008 |
| Předmět: | |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1051/0004-6361:200809775 |
| Popis: | Aims: We build a catalogue PPM-Extended (PPMX) on the ICRS system which is complete down to a well-defined limiting magnitude and contains the best presently available proper motions to be suited for kinematical studies in the Galaxy. Methods: We perform a rigorous weighted least-squares adjustment of individual observations, spread over more than a century, to determine mean positions and proper motions. The stellar content of PPMX is taken from GSC 1.2 supplemented by catalogues like ARIHIP, PPM and Tycho-2 at the bright end. All observations have been weighted according to their individual accuracy. The catalogue has been screened towards rejecting false entries in the various source catalogues. Results: PPM-Extended (PPMX) is a catalogue of 18,088,920 stars containing astrometric and photometric information. Its limiting magnitude is about 15.2 in the GSC photometric system. PPMX consists of three parts: a) a survey complete down to R_U = 12.8 in the magnitude system of UCAC2; b) additional stars of high-precision proper motions, and c) all other stars from GSC 1.2 identified in 2MASS. The typical accuracy of the proper motions is 2mas/y for 66 percent of the survey stars (a) and the high-precision stars (b), and about 10 mas/y for all other stars. PPMX contains photometric information from ASCC-2.5 and 2MASS. Comment: 9 pages, 8 figures, accepted for publication in Astronomy and Astrophysics |
| Databáze: | arXiv |
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