Patterns, an efficient way to analyse the p-mode content in rapidly rotating stars

¹ Instituto de Astrofísica e Ciências do Espaço, Universidade do Porto, CAUP, Rua das Estrelas, PT4150-762 Porto, Portugal
² Institut de Recherche en Astrophysique et Planètologie (IRAP), CNRS : UMR5277
³ South African Astronomical Observatory (SAAO), P. O. Box 9 Observatory 7935 Cape Down, South Africa
⁴ School of Physics and Astronomy, University of Birmingham (UoB), Edgbaston, Birmingham, B15 2TT, United Kingdom
⁵ Instituto de Astrofísica de Andalucía (CSIC), CP3004, Granada, Spain

^a e-mail: agh@astro.up.pt. AGH acknowledges support from the EC Project SPACEINN (FP7-SPACE2012-312844), from project PTDC/CTE-AST/098754/2008 from FCT (Portugal) and from FCT-MEC (Portugal) through a fellowship (SFRH/BPD/80619/2011).

Published online: 23 September 2015

Abstract

High precision photometric observations from space has led to the detection of hundreds of frequencies in the light curves of δ Scuti pulsators. In this work, we analyzed a sample of Kepler δ Sct stars to search for frequency patterns in the p-mode regime. To avoid g-modes, we looked at the mode density histogram (MDH). We then used the Fourier transform technique (FT), histograms of frequency differences (HFD) and Echelle diagrams (ED) to find periodicities in the frequency content. We compared the results with those expected for SCF rotating models [4] with the aim of identifying large separations and rotational splittings.