Global asteroseismology of 19,000 red giants in the TESS Continuous Viewing Zones

TL;DR

This paper presents a comprehensive asteroseismic catalog of over 19,000 red giants observed by TESS, utilizing advanced pipelines and neural networks to determine stellar properties with high precision for Galactic studies.

Contribution

The study provides the largest TESS-based red giant asteroseismic catalog, employing novel classification and measurement techniques to enhance stellar parameter accuracy.

Findings

Identified an 80% increase in known oscillating red giants at TESS magnitude > 8.

Achieved 1.5% and 1% precision in $ u_{max}$ and $ m igtriangleup u$ measurements.

Validated seismic radii against Gaia data showing excellent agreement.

Abstract

TESS (Transiting Exoplanet Survey Satellite) has produced long-term photometry for millions of stars across the sky. In this work, we present an asteroseismic catalogue of 19,151 red giants in the TESS Continuous Viewing Zones using sectors 1--87 (Years 1--7). We visually assessed the power spectra for oscillations, and then applied the computationally efficient nuSYD method to confirm reliability. We identified an increase of 80% in the number of previously known oscillating red giants at a TESS magnitude $>$ 8. We determined the frequency of maximum power ($\rm \nu_{max}$) and the large frequency separation ($\rm \Delta \nu$) using the pySYD pipeline, achieving typical precisions of 1.5% and 1%, respectively. We classified the stars into Red Giant Branch (RGB) and Core Helium Burning (CHeB) classes using a Convolutional Neural Network. Using spectroscopic data for 10,298 stars with reliable asteroseismic measurements, we have been able to measure stellar mass and radii with precisions of 7.5% and 2.8%, which is comparable to that from 4-yr $Kepler$ data. A comparison of the seismic radii with Gaia radii shows excellent agreement. With three years of TESS data, the asteroseismic parameters are precise enough to identify the RGB bump and delineate the Zero Age Helium Burning edge. Combined with astrometric data, these parameters reveal established trends across the Galactic plane, providing a valuable set of uniformly determined asteroseismic parameters for Galactic Archaeology.