355 citations · 2.3k across the 49 of their papers we have counts for
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Chemical Abundances of Red Giant Stars in the Globular Cluster M107 (NGC 6171)
Julia E. O'Connell, Christian I. Johnson, Catherine A. Pilachowski +1
We present chemical abundances of Al and several Fe-Peak and neutron-capture elements for 13 red giant branch stars in the Galactic globular cluster NGC 6171 (M107). The abundances…
Empirical determination of the integrated red giant and horizontal branch stellar mass loss in omega Centauri
Iain McDonald, Christian I. Johnson, Albert A. Zijlstra
We herein determine the average integrated mass loss from stars stars belonging to the dominant metal-poor population ([Fe/H] ~ --1.7) of the Galactic globular cluster omega Centau…
Multiple populations in Omega Centauri: a cluster analysis of spectroscopic data
Raffaele Gratton, Christian I. Johnson, Sara Lucatello +2
Omega Cen is composed of several stellar populations. Their history might allow us to reconstruct the evolution of this complex object. We performed a statistical cluster analysis…
Spitzer spectra of evolved stars in omega Centauri and their low-metallicity dust production
Iain McDonald, Jacco Th. van Loon, Gregory C. Sloan +7
Dust production is explored around 14 metal-poor ([Fe/H] = -1.91 to -0.98) giant stars in the Galactic globular cluster omega Centauri using new Spitzer IRS spectra. This sample in…
Alpha Enhancement and the Metallicity Distribution Function of Plaut's Window
Christian I. Johnson, R. Michael Rich, Jon P. Fulbright +2
We present Fe, Si, and Ca abundances for 61 giants in Plaut's Window (l=-1,b=-8.5) and Fe abundances for an additional 31 giants in a second, nearby field (l=0,b=-8) derived from h…