The radial age distribution of Galactic Cepheids

Abstract

The aim of this work is to model the radial age distribution of Galactic Classical Cepheids. We create a simulation of star particles in the Galactic disc using a simple recipe and associate them with stellar evolutionary models. We then select Classical Cepheids from the simulation and test in qualitative terms which definition of the instability strip limits agrees better with the observational data. We show that the two key ingredients for a correct modelling of the observed Galactocentric radius vs. age distribution in the Milky Way are the radial-metallicity gradient and a metallicity dependence of the instability strip