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1999AJ....117.2308W - Astron. J., 117, 2308-2328 (1999/May-0)
Spectroscopy of hot stars in the galactic halo. II. The identification and classification of horizontal-branch and other A-type stars.
WILHELM R., BEERS T.C. and GRAY R.O.
Abstract (from CDS):
A comparison of our method with high signal-to-noise ratio spectra of standard stars indicates a scatter in the derived parameters of σ(Teff)=±250 K, σ(log g)=±0.14 dex, and σ([Fe/H])=±0.12 dex. This precision allows for a separation of low surface gravity FHB and other, generally higher surface gravity, A-type (and somewhat later) stars. We also develop a synthetic-template comparison technique, which is very effective in the identification of metallic-line and peculiar A-type stars.
A detailed investigation of the influence of noise in the spectra on the determination of physical parameters shows that, for spectra with signal-to-noise ratios in the range 10<S/N<20, the scatter in estimated surface gravity, σ(log g)=±0.25 dex, is sufficiently small to keep the noise-induced misclassification rate for the hot stars we consider to less than 10%. Effective temperatures of precision σ(Teff)=±225 K and metallicities of precision σ([Fe/H])=±0.3 dex can be obtained.
Abstract Copyright: ∼
Journal keyword(s): Galaxy: Halo - Stars: Horizontal-Branch - Stars: Population II
VizieR on-line data: <Available at CDS (J/AJ/117/2308): table1.dat>
Simbad objects: 102
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