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SCALING UP ENSEMBLE MODELLING OF GRAVITY-MODE PULSATORS WITH GAIA AND TESS

Mombarg, Joey; Aerts, Conny; Van Reeth, Timothy; Hey, Daniel

Abstract

Abstract: Measurements of internal rotation frequencies and chemical mixing efficiencies of (main sequence) gravity mode pulsators have enabled the rigorous testing of the state-of-the-art stellar structure and evolution models. We prepare for future large ensemble modelling of gravity-mode pulsators by relying on a new sample of such stars recently discovered from the 3rd Data Release of the Gaia mission and confirmed by space photometry from TESS. This sample of potential asteroseismic targets is about 23 times larger than the Kepler sample. We use the effective temperature and luminosity inferred from Gaia to deduce evolutionary masses, convective core masses, radii, and ages for ∼14,000 gravity-mode pulsators classified as such from their TESS light curves. We do so by constructing dedicated grids of evolutionary models for rotating stars with input physics from the asteroseismic calibrations of Kepler γ Doradus pulsators. We find the new gravity-mode pulsators to cover an extended observational instability region covering masses from about 1.3 to about 9 M⊙. In this talk, I will provide their mass-luminosity and mass-radius relations, as well as convective core masses. The results suggest that oscillations excited by the opacity mechanism occur uninterruptedly for the mass range above about 2 M⊙, where stars have a radiative envelope aside from thin convection zones in their excitation layers. Furthermore, for a subsample of these stars, we relied on asteroseismic properties of Kepler γ Doradus and slowly pulsating B stars to derive the near-core rotation frequency of the Gaia-discovered pulsators from their dominant prograde dipole gravito-inertial pulsation mode, in addition to the age estimate. I will discuss the evolution of the rotation frequency of ~2,400 stars along the main sequence. A decline of the rotation frequency with a factor of two is seen during the main-sequence evolution for this population of field stars, which covers a mass range from 1.3 to 7 M⊙.

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v Z SCALING UP ENSEMBLE MODELLING OF GRAVITY-MODE PULSATORS WITH GAIA AND TESS TASC9/KASC16 2025 [email protected] jmombarg.github.io/PersonalWebsite/ Joey Mombarg Conny Aerts Timothy Van Reeth Daniel Hey Funded by the European Union v Z SCALING UP ENSEMBLE MODELLING OF GRAVITY-MODE PULSATORS WITH GAIA AND TESS TASC9/KASC16 2025 [email protected] jmombarg.github.io/PersonalWebsite/ Joey Mombarg Conny Aerts Timothy Van Reeth Daniel Hey Funded by the European Union TASC9/KASC16 2025 - Vienna Joey Mombarg THE TRILOGY 3 “The two grids” “The fellowship of the Gaia g-mode pulsators” “The rotation of the subsample” TASC9/KASC16 2025 - Vienna Joey Mombarg THE FELLOWSHIP OF THE GAIA G-MODE PULSATORS ▸106,207 Gaia DR3 gand p-mode pulsators (Gaia Collaboration et al. 2023) ▸15,062 g-mode pulsator candidates based on the dominant frequency (Aerts et al. 2023) ▸Sample of Hey & Aerts (2024): —> 58,970 stars with TESS-Gaia LCs —> 70% same dominant frequency —> classification with Random Forest 4 classification probability ‘ Dor/SPB’ or ‘hybrid’ γ ~3200 ~14,000 TASC9/KASC16 2025 - Vienna Joey Mombarg THE TWO GRIDS - PARAMETER ESTIMATION 5 L⋆,TeffM⋆,Xc,mcc,R⋆ ▸Metallicity unknown —> two grids for [M/H] = 0 and -0.5 (de Laverny et al. 2024). rotation rate mass chemical mixing efficiency fov GSP-Phot TASC9/KASC16 2025 - Vienna Joey Mombarg THE TWO GRIDS - PARAMETER ESTIMATION 6 L⋆,TeffM⋆,Xc,mcc,R⋆ ▸Metallicity unknown —> two grids for [M/H] = 0 and -0.5 (de Laverny et al. 2024).radius mixing efficiency fCBM GSP-Phot TASC9/KASC16 2025 - Vienna Joey Mombarg INTERPOLATION BETWEEN GRID POINTS ▸Potential of conditional normalising flows (CNFs) to emulate stellar grids demonstrated by Hon, Li & Ong (2024). ▸CNF trained on 155,000 points —> sample ~ 1 million (uniform in ). ▸Compute likelihood for a each point sampled —> KDE with likelihoods as weights. Xc/Xini 7 y=f(z)y∼p(y|c) M⋆,fCBM,ω0 ∼p0(z) TASC9/KASC16 2025 - Vienna Joey Mombarg DISTRIBUTIONS FOR [M/H]=-0.5 8 mass core mass relative age radius Mombarg et al. (2024) Salpeter IMF, dN/dM∝M−2.35 ~14,000 stars TASC9/KASC16 2025 - Vienna Joey Mombarg IS THERE A GAP BETWEEN DORS AND SPBS? γ ▸One-sample Kolomogorov-Smirnov test —> mass distribution compatible with Salpeter IMF down to ~2.2-2.5 . ▸Sample above 4 likely undersampled. ▸-mechanism active uninterruptedly above ~2 . ▸Flux blocking highly effective. M⊙ M⊙ κ M⊙ 9 Z= 0.014 Z= 0.0045 Mombarg et al. (2024) TASC9/KASC16 2025 - Vienna Joey Mombarg UPPER LIMITS ON DIFFERENTIAL ROTATION (CORE/SURFACE) ▸Gaia v_broad meaningful approximation of . ▸Upper limits for ~1000 stars. 2πR⋆⋅fsurf sin i 16 relative age [M/H] = 0 [M/H] = −0.25 [M/H] = −0.5 Aerts et al. (2025) (fsurf sin i≤fsurf) TASC9/KASC16 2025 - Vienna Joey Mombarg CONCLUSIONS ▸TESS/Gaia synergy powerful tool for starting large ensemble modelling of gmode pulsators. ▸Opacity ( ) mechanism active uninterruptedly above ~2 . ▸Recipe to deduce near-core rotation frequency from dominant prograde dipole mode facilitates study of rotational evolution of large samples. κ M⊙ 17 [email protected] Aerts, Van Reeth, Mombarg & Hey (2025) Mombarg, Aerts, Van Reeth & Hey (2024) Hey & Aerts (2024)