Study of rotational splittings in δ Scuti stars using pattern finding techniques. Issue 4 (18th June 2021)

• Record Type: Journal Article
• Authors: Ramón-Ballesta, A; García Hernández, A; Suárez, J C; Rodón, J R; Pascual-Granado, J; Garrido, R
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 505:Issue 4(2021)
• Page Start: 6217
• Page End: 6224
• Publication Date: 2021-06-18
• Subjects: binaries: eclipsing -- stars: oscillations -- stars: rotation -- stars: variables: Scuti; Astronomy -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnras/stab1719
• Languages: English
• ISSNs: 0035-8711

Abstract

ABSTRACT: Detecting and understanding rotation in stellar interiors is nowadays one of the unsolved problems in stellar physics. Asteroseismology has been able to provide insights on rotation for the Sun, solar-like stars, and compact objects like white dwarfs. However, this is still very difficult for intermediate-mass stars. These stars are moderate-to-rapid rotators. Rotation splits and shifts the oscillation modes, which makes the oscillation spectrum more complex and harder to interpret. Here we study the oscillation patterns of a sample of benchmark δ Sct stars belonging to eclipsing binary systems with the objective of finding the frequency spacing related to the rotational splitting (δ r ). For this task, we combine three techniques: the Fourier transform, the autocorrelation function, and the histogram of frequency differences. The last two showed a similar behaviour. For most of the stars, it was necessary to determine the large separation (Δν) prior to spot δ r . This is the first time we may clearly state that one of the periodicities present in the p modes oscillation spectra of δ Sct stars corresponds to the rotational splitting. This is true independent of the stellar rotation rate. These promising results pave the way to finding a robust methodology to determine rotational splittings from the oscillation spectra of δ Sct stars and, thus, understanding the rotational profile of intermediate-mass pulsating stars.