Title: DDO metallicity calibration for metal-deficient red giants and the disk-halo transition
Abstract: DDO abundance estimates for metal-deficient field red giants from the survey by Norris et al., (1985) are compared with high dispersion spectroscopic abundances and recalibrated uvby photometry. The DDO abundances are shown to deviate from the standard system by an amount which is metallicity dependent, i.e., a simple offset cannot transform the DDO data to the spectroscopic system. A recalibration of the DDO photometry demonstrates that the old DDO calibration provides reliable (Fe/H) estimates near -0.8 and -2.3, but systematically underestimates the metallicity of stars near -1.2 by about 0.5 dex. Reanalysis of the red giant sample of Norris et al. leads to a metallicity distribution much closer to that of the globular clusters while significantly decreasing the fracion of metal-weak disk stars. A possible explanation for origin of the discrepancy is that the clusters of intermediate (Fe/H) used in the DDO calibration are not representative of the field stars at the same (Fe/H).
Publication Year: 1994
Publication Date: 1994-04-01
Language: en
Type: article
Indexed In: ['crossref']
Access and Citation
Cited By Count: 26
AI Researcher Chatbot
Get quick answers to your questions about the article from our AI researcher chatbot