217 citations · 855 across the 12 of their papers we have counts for
5 papers · 1 filter
The Most Metal-Poor Stars. IV. The Two Populations With [Fe/H] < -3.0
John E. Norris, David Yong, M. S. Bessell +8
We discuss the carbon-normal and carbon-rich populations of Galactic halo stars having [Fe/H] < -3.0, utilizing chemical abundances from high-resolution, high-S/N model-atmosphere…
The Most Metal-Poor Stars. III. The Metallicity Distribution Function and CEMP Fraction
David Yong, John E. Norris, M. S. Bessell +6
We examine the metallicity distribution function (MDF) and fraction of carbon-enhanced metal-poor (CEMP) stars in a sample that includes 86 stars with [Fe/H] < -3.0, based on high-…
The Most Metal-Poor Stars. I. Discovery, Data, and Atmospheric Parameters
John E. Norris, M. S. Bessell, David Yong +7
We report the discovery of 34 stars in the Hamburg/ESO Survey for metal-poor stars and the Sloan Digital Sky Survey that have [Fe/H] < -3.0. Their median and minimum abundances are…
The AGB population of NGC 6822: distribution and the C/M ratio from JHK photometry
L. F. Sibbons, S. G. Ryan, M. -R. L. Cioni M. Irwin +1
NGC 6822 is an irregular dwarf galaxy and part of the Local Group. Its close proximity and apparent isolation provide a unique opportunity to study galactic evolution without any o…
The barium isotopic fractions in five metal-poor stars
A. J. Gallagher, S. G. Ryan, A. Hosford +3
We provide measurements of the Ba isotopic fractions for five metal-poor stars derived with an LTE analysis using 1D model stellar atmospheres. We use high resolution (R\equivλ/Δλ=…