Detection of period-spacing patterns due to the gravity modes of rotating dwarfs in the TESS southern continuous viewing zone

TL;DR

This paper presents a catalog of 140 gravity-mode period-spacing patterns in 108 intermediate-mass stars observed by TESS, enabling advanced asteroseismic studies of stellar interiors and rotation.

Contribution

It introduces a novel method for detecting period-spacing patterns and provides the first high-quality catalog of such patterns in TESS data for rotating dwarfs.

Findings

First catalog of gravity-mode period-spacing patterns in TESS data

Detected 140 patterns in 106 Gamma Doradus and 2 SPB stars

Half of the patterns have 7 or more measured modes

Abstract

Context: the theory of stellar evolution presents shortcomings when confronted with asteroseismic probes of interior physical properties. The differences between observations and theory are often great because stellar models have mainly been calibrated from observables connected to the surface of stars. Period-spacing patterns caused by gravity modes are a particularly powerful asteroseismic tool that are useful for probing the near-core rotation and mixing of chemical elements in main-sequence stars with convective cores. Aims: we aim to compose a catalog of intermediate-mass stars in the TESS southern continuous viewing zone to reveal period-spacing patterns caused by gravity modes for use in future asteroseismic modeling. Methods: TESS full frame images were inspected to select stars of intermediate- and high-mass using color-magnitude criteria. Light curves were extracted from custom masks per star, adopting stringent constraints on the aperture masks and contamination. The extracted light curves were subject to iterative prewhitening to detect gravity modes. We developed a method based on the assumption that period spacings are an approximately linear function of the mode periods to build a template pattern. This template was used to extract the patterns and their bootstrap uncertainties. Results: our TESS catalog of high-quality period-spacing patterns is the first of its kind and contains 140 gravity-mode patterns in 106 Gamma Doradus stars and 2 slowly pulsating B-type stars. Half of these patterns contain 7 or more measured mode periods and the longest pattern contains 20 modes. We provide the community with a convenient software tool to search for period-spacing patterns and to process the extracted light curves. Conclusions: our catalog offers a fruitful starting point for future gravity-mode asteroseismology of rotating dwarfs with convective cores in the southern hemisphere.