PPM-Extended (PPMX) - a catalogue of positions and proper motions
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.
Keywords
Cite
@article{arxiv.0806.1009,
title = {PPM-Extended (PPMX) - a catalogue of positions and proper motions},
author = {S. Roeser and E. Schilbach and H. Schwan and N. V. Kharchenko and A. E. Piskunov and R. -D. Scholz},
journal= {arXiv preprint arXiv:0806.1009},
year = {2009}
}
Comments
9 pages, 8 figures, accepted for publication in Astronomy and Astrophysics