Metallicity estimates of Galactic Cepheids based on Walraven photometry

S. Pedicelli; J. Lub; J. W. Pel; B. Lemasle; G. Bono; P. Francois; D. Laney; A. Piersimoni; F. Primas; M. Romaniello; R. Buonanno; F. Caputo; S. Cassisi; F. Castelli; A. Pietrinferni; J. Pritchard

arXiv · 0712.3006

Metallicity estimates of Galactic Cepheids based on Walraven photometry

S. Pedicelli·J. Lub·J. W. Pel·B. Lemasle·G. Bono·P. Francois·D. Laney·A. Piersimoni·F. Primas·M. Romaniello·R. Buonanno·F. Caputo·S. Cassisi·F. Castelli·A. Pietrinferni·J. Pritchard

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Abstract

We present new empirical and theoretical calibrations of two photometric metallicity indices based on Walraven photometry. The empirical calibration relies on a sample of 48 Cepheids for which iron abundances based on high resolution spectra are available in the literature. They cover a broad range in metal abundance (-0.5 < [Fe/H] < +0.5) and the intrinsic accuracy of the Metallicity Index Color (MIC) relations is better than 0.2 dex. The theoretical calibration relies on a homogeneous set of scaled-solar evolutionary tracks for intermediate-mass stars and on pulsation predictions concerning the topology of the instability strip. The metal content of the adopted evolutionary tracks ranges from Z=0.001 to Z=0.03 and the intrinsic accuracy of the MIC relations is better than 0.1 dex.

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S. Pedicelli, J. Lub, J. W. Pel, B. Lemasle, G. Bono, P. Francois, D. Laney, A. Piersimoni, F. Primas, M. Romaniello, R. Buonanno, F. Caputo, S. Cassisi, F. Castelli, A. Pietrinferni, J. Pritchard. 2007-12-18. Metallicity estimates of Galactic Cepheids based on Walraven photometry. https://arxiv.org/abs/0712.3006

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