Asteroseismology and Buoyancy Glitch Inversion with Fourier Spectra of Gravity Mode Period Spacings
Fuente:
arXiv
Saved in:
| Main Author: | |
|---|---|
| Format: | Preprint |
| Published: |
2025
|
| Subjects: | |
| Online Access: | |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1866911482964344832 |
|---|---|
| author | Guo, Zhao |
| author_facet | Guo, Zhao |
| contents | We investigate the small, quasi-periodic modulations seen in the gravity-mode period spacings of pulsating stars. These ``wiggles'' are produced by buoyancy glitches -- sharp features in the buoyancy frequency ($N$) caused by composition transitions and the convective-radiative interface. Our method takes the Fourier transform of the period-spacing series, $FT(ΔP_k)$ as a function of radial order $k$. We show that $FT(ΔP_k)$ traces the radial derivative of the normalized glitch profile $δN/N$ with respect to the normalized buoyancy radius; peaks in $FT(ΔP_k)$ therefore pinpoint jump/drop locations in $N$ and measure their sharpness. We also note that the Fourier transform of relative period perturbations (deviations from asymptotic values), $FT(δP/P)$, directly recovers the absolute value of the glitch profile $|δN/N|$, enabling a straightforward inversion for the internal structure.
The dominant $FT(ΔP_k)$ frequency correlates tightly with central hydrogen abundance ($X_c$) and thus with stellar age for slowly pulsating B-stars, with only weak mass dependence. Applying the technique to MESA stellar models and to observed slowly pulsating B-stars and $γ$ Dor pulsators, we find typical glitch amplitudes $δN/N \lesssim 0.01$ and derivative magnitudes $\lesssim 0.1$, concentrated at chemical gradients and the convective boundary. This approach enables fast, ensemble asteroseismology of g-mode pulsators, constrains internal mixing and ages, and can be extended to other classes of pulsators, with potential links to tidal interactions in binaries. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2511_05780 |
| institution | arXiv |
| publishDate | 2025 |
| record_format | arxiv |
| spellingShingle | Asteroseismology and Buoyancy Glitch Inversion with Fourier Spectra of Gravity Mode Period Spacings Guo, Zhao Solar and Stellar Astrophysics We investigate the small, quasi-periodic modulations seen in the gravity-mode period spacings of pulsating stars. These ``wiggles'' are produced by buoyancy glitches -- sharp features in the buoyancy frequency ($N$) caused by composition transitions and the convective-radiative interface. Our method takes the Fourier transform of the period-spacing series, $FT(ΔP_k)$ as a function of radial order $k$. We show that $FT(ΔP_k)$ traces the radial derivative of the normalized glitch profile $δN/N$ with respect to the normalized buoyancy radius; peaks in $FT(ΔP_k)$ therefore pinpoint jump/drop locations in $N$ and measure their sharpness. We also note that the Fourier transform of relative period perturbations (deviations from asymptotic values), $FT(δP/P)$, directly recovers the absolute value of the glitch profile $|δN/N|$, enabling a straightforward inversion for the internal structure. The dominant $FT(ΔP_k)$ frequency correlates tightly with central hydrogen abundance ($X_c$) and thus with stellar age for slowly pulsating B-stars, with only weak mass dependence. Applying the technique to MESA stellar models and to observed slowly pulsating B-stars and $γ$ Dor pulsators, we find typical glitch amplitudes $δN/N \lesssim 0.01$ and derivative magnitudes $\lesssim 0.1$, concentrated at chemical gradients and the convective boundary. This approach enables fast, ensemble asteroseismology of g-mode pulsators, constrains internal mixing and ages, and can be extended to other classes of pulsators, with potential links to tidal interactions in binaries. |
| title | Asteroseismology and Buoyancy Glitch Inversion with Fourier Spectra of Gravity Mode Period Spacings |
| topic | Solar and Stellar Astrophysics |
| url | https://arxiv.org/abs/2511.05780 |