New homogeneous iron abundances of double-mode Cepheids from high-resolution echelle spectroscopy

K. Sziladi; J. Vinko; E. Poretti; L. Szabados; M. Kun

doi:10.1051/0004-6361:20077539

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arXiv · 0707.2530

New homogeneous iron abundances of double-mode Cepheids from high-resolution echelle spectroscopy

K. Sziladi·J. Vinko·E. Poretti·L. Szabados·M. Kun

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Abstract

Aims: We define the relationship between the double-mode pulsation of Cepheids and metallicity in a more accurate way, determine the empirical metallicities of double-mode Cepheids from homogeneous, high-resolution spectroscopic data, and study of the period-ratio -- metallicity dependence. Methods: The high S/N echelle spectra obtained with the FEROS spectrograph were analyzed using a self-developed IRAF script, and the iron abundances were determined by comparing with synthetic spectra assuming LTE. Results: Accurate [Fe/H] values of 17 galactic beat Cepheids were determined. All these stars have solar or slightly subsolar metallicity. Their period ratio P1/P0 shows strong correlation with their derived [Fe/H] values. The corresponding period ratio -- metallicity relation has been evaluated.

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K. Sziladi, J. Vinko, E. Poretti, L. Szabados, M. Kun. 2007-07-17. New homogeneous iron abundances of double-mode Cepheids from high-resolution echelle spectroscopy. https://doi.org/10.1051/0004-6361%3A20077539

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