SPACE VELOCITIES OF SOUTHERN GLOBULAR-CLUSTERS .1. ASTROMETRIC TECHNIQUES AND FIRST RESULTS

Citation
Di. Dinescu et al., SPACE VELOCITIES OF SOUTHERN GLOBULAR-CLUSTERS .1. ASTROMETRIC TECHNIQUES AND FIRST RESULTS, The Astronomical journal, 114(3), 1997, pp. 1014-1029
Citations number
69
Categorie Soggetti
Astronomy & Astrophysics
Journal title
ISSN journal
00046256
Volume
114
Issue
3
Year of publication
1997
Pages
1014 - 1029
Database
ISI
SICI code
0004-6256(1997)114:3<1014:SVOSG.>2.0.ZU;2-6
Abstract
We present the first results of a program involving the determination of absolute proper-motions with respect to galaxies for a sample of so uthern globular clusters. Special attention has been given to understa nding the systematics related to the plate material, the behavior of d ifferent reduction procedures, and the contribution of the reference-s ystem proper-motion distribution and mean motion to the final solution . We have developed a local-type astrometric solution which overcomes most of the systematics, such that our limit in the absolute proper-mo tion precision is set by the centering accuracy and numbers of images of galaxies and cluster stars. Space velocities are derived for NGC 28 8, NGC 1851, NGC 6362, NGC 6584, and NGC 6752 and their kinematics are discussed in the view of halo subdivisions and Galaxy formation scena rios. (C) 1997 American Astronomical Society.