The new Basel high-latitude field star survey of the Galaxy
I. General introduction, methodology and first analysis
Roland Buser 1,
Jianxiang Rong 2 and
Salih Karaali 3
Received 1 August 1997 / Accepted 10 November 1997
This is the first in a series of papers devoted to the determination of Galactic structure from the new homogeneous catalog of photographic RGU field star data in fourteen high-latitude directions. We give a general description of the motivation for this work, the construction of the observational data base, and the structural Galaxy models designed for its analysis. In particular, we provide a concise yet comprehensive account of the statistical methodology used for determining reliable constraints to the model parameters. Preliminary results obtained from the first-half sample of seven fields are discussed to demonstrate the significance of the approach.
Our best models suggest that the thick disk component has a local density of relative to the thin disk, an exponential scale height of kpc, and mean metallicity dex with dispersion dex. However, because the present data cannot exclude the existence of a vertical metallicity gradient dex/kpc, a sharper picture of the thick disk metallicity structure must await the analysis of the full-survey data in 14 fields.
Key words: Galaxy: abundances Galaxy: general Galaxy: stellar content Galaxy: structure
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© European Southern Observatory (ESO) 1998
Online publication: March 3, 1998