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arXiv · astro-ph/9905264

Empirical calibration of the λ4000 Åbreak

Javier Gorgas·Nicolas Cardiel·Santos Pedraz·Jesus Gonzalez
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Abstract

Empirical fitting functions, describing the behaviour of the λ4000 Åbreak, D_4000, in terms of effective temperature, metallicity and surface gravity, are presented. For this purpose, the break has been measured in 392 stars from the Lick/IDS Library. We have followed a very detailed error treatment in the reduction and fitting procedures, allowing for a reliable estimation of the break uncertainties. This calibration can be easily incorporated into stellar population models to provide accurate predictions of the break amplitude for, relatively old, composite systems.

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Javier Gorgas, Nicolas Cardiel, Santos Pedraz, Jesus Gonzalez. 1999-05-20. Empirical calibration of the λ4000 Åbreak. https://doi.org/10.1051/aas%3A1999375

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