Modelling of multimode radially pulsating high-amplitude δ Scuti stars from the OGLE Galactic bulge sample

Abstract

ABSTRACT Thanks to relatively firm mode identification, possible based only on period ratios, high-amplitude δ Scuti stars pulsating in at least three radial modes are promising targets for asteroseismic inference. In this study, we used the most numerous sample of HADS from the OGLE inner bulge fields that likely pulsate in either three or four radial modes simultaneously. We have computed a grid of pulsation models along evolutionary tracks and determined the physical parameters of stars by matching their pulsation periods and period ratios. For 176 HADS, we determined physical parameters, i.e. masses, luminosities, effective temperatures, metallicities, and ages. We present the distribution of physical parameters and discuss their properties. We selected 16 candidates for SX Phoenicis stars.