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arXiv · 0806.1009

PPM-Extended (PPMX) - a catalogue of positions and proper motions

S. Roeser·E. Schilbach·H. Schwan·N. V. Kharchenko·A. E. Piskunov·R. -D. Scholz
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Abstract

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.

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S. Roeser, E. Schilbach, H. Schwan, N. V. Kharchenko, A. E. Piskunov, R. -D. Scholz. 2008-06-05. PPM-Extended (PPMX) - a catalogue of positions and proper motions. https://doi.org/10.1051/0004-6361:200809775

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