A COMPARISON of STELLAR ELEMENTAL ABUNDANCE TECHNIQUES and MEASUREMENTS

Natalie R. Hinkel, Patrick Young, Michael D. Pagano, Steven Desch, Ariel Anbar, Vardan Adibekyan, Sergi Blanco-Cuaresma, Joleen K. Carlberg, Elisa Delgado Mena, Fan Liu, Thomas Nordlander, Sergio G. Sousa, Andreas Korn, Pieter Gruyters, Ulrike Heiter, Paula Jofré, Nuno C. Santos, Caroline Soubiran

Research output: Contribution to journalArticle

28 Scopus citations

Abstract

Stellar elemental abundances are important for understanding the fundamental properties of a star or stellar group, such as age and evolutionary history, as well as the composition of an orbiting planet. However, as abundance measurement techniques have progressed, there has been little standardization between individual methods and their comparisons. As a result, different stellar abundance procedures determine measurements that vary beyond the quoted error for the same elements within the same stars. The purpose of this paper is to better understand the systematic variations between methods and offer recommendations for producing more accurate results in the future. We invited a number of participants from around the world (Australia, Portugal, Sweden, Switzerland, and the United States) to calculate 10 element abundances (C, O, Na, Mg, Al, Si, Fe, Ni, Ba, and Eu) using the same stellar spectra for four stars (HD 361, HD 10700, HD 121504, and HD 202206). Each group produced measurements for each star using (1) their own autonomous techniques, (2) standardized stellar parameters, (3) a standardized line list, and (4) both standardized parameters and a line list. We present the resulting stellar parameters, absolute abundances, and a metric of data similarity that quantifies the homogeneity of the data. We conclude that standardization of some kind, particularly stellar parameters, improves the consistency between methods. However, because results did not converge as more free parameters were standardized, it is clear there are inherent issues within the techniques that need to be reconciled. Therefore, we encourage more conversation and transparency within the community such that stellar abundance determinations can be reproducible as well as accurate and precise.

Original languageEnglish (US)
Article number4
JournalAstrophysical Journal, Supplement Series
Volume226
Issue number1
DOIs
StatePublished - Sep 1 2016

    Fingerprint

Keywords

  • stars: abundances
  • stars: individual (HD 361, HD 10700, HD 121504, HD 202206)
  • techniques: spectroscopic

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

Cite this

Hinkel, N. R., Young, P., Pagano, M. D., Desch, S., Anbar, A., Adibekyan, V., Blanco-Cuaresma, S., Carlberg, J. K., Mena, E. D., Liu, F., Nordlander, T., Sousa, S. G., Korn, A., Gruyters, P., Heiter, U., Jofré, P., Santos, N. C., & Soubiran, C. (2016). A COMPARISON of STELLAR ELEMENTAL ABUNDANCE TECHNIQUES and MEASUREMENTS. Astrophysical Journal, Supplement Series, 226(1), [4]. https://doi.org/10.3847/0067-0049/226/1/4