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Precision Chemical Abundance Measurements

Published online by Cambridge University Press:  05 March 2015

David Yong
Affiliation:
Research School of Astronomy and Astrophysics, The Australian National University, Weston, ACT 2611, Australia email: yong@mso.anu.edu.au
Frank Grundahl
Affiliation:
Department of Physics and Astronomy, Aarhus University, Ny Munkegade, 8000, Aarhus C, Denmark
Jorge Meléndez
Affiliation:
Departamento de Astronomia do IAG/USP, Universidade de Sao Paulo, Rua do Matao 1226, Sao Paulo, 05508-900, SP, Brasil
John E. Norris
Affiliation:
Research School of Astronomy and Astrophysics, The Australian National University, Weston, ACT 2611, Australia email: yong@mso.anu.edu.au
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Abstract

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This talk covers preliminary work in which we apply a strictly differential line-by-line chemical abundance analysis to high quality UVES spectra of the globular cluster NGC 6752. We achieve extremely high precision in the measurement of relative abundance ratios. Our results indicate that the observed abundance dispersion exceeds the measurement uncertainties and that many pairs of elements show significant correlations when plotting [X1/H] vs. [X2/H]. Our tentative conclusions are that either NGC 6752 is not chemically homogeneous at the ≃0.03 dex level or the abundance variations and correlations signify star-to-star He abundance variations.

Type
Contributed Papers
Copyright
Copyright © International Astronomical Union 2015 

References

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