Probing the properties of convective cores through g modes : high-order g modes in SPB and γ Doradus stars
By A. Miglio, J. Montalbán, A. Noels, P. Eggenberger. 2008
159 citations recorded by the source corpus.
In main-sequence stars, the periods of high-order gravity modes are sensitive probes of stellar cores and, in particular, of the chemical composition gradient that develops near the outer edge of the convective core. We present an analytical approximation of high-order g modes that takes into account the effect of the μ gradient near the core. We show that in main-sequence models, similarly to the case of white dwarfs, the periods of high-order gravity modes are accurately described by a uniform period spacing superposed to an oscillatory component. The periodicity and amplitude of such component are related, respectively, to the location and sharpness of the μ gradient. We investigate the properties of high-order gravity modes for stellar models in a mass domain range between 1 and 10 M⊙, and the effects of the stellar mass, evolutionary state and extra-mixing processes on period spacing features. In particular, we show that for models of a typical Slowly Pulsating B (SPB) star, a chemical mixing that could likely be induced by the slow rotation observed in these stars is able to significantly change the g-mode spectra of the equilibrium model. Prospects and challenges for the asteroseismology of γ Doradus and SPB stars are also discussed.
Subfields: Astronomy and Astrophysics, Instrumentation
View Paper: https://www.semanticscholar.org/paper/d5d4befbc24e7a92eb939e6dba095c40166131ab
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Citations in the corpus
- HYBRID γ DORADUS–δ SCUTI PULSATORS: NEW INSIGHTS INTO THE PHYSICS OF THE OSCILLATIONS FROM KEPLER OBSERVATIONS (2010, background): “Miglio et al. (2008) also considered high-order g modes to probe the properties of convective cores in Slowly Pulsating B and γ Dor stars.”
- Modules for Experiments in Stellar Astrophysics (MESA): Pulsating Variable Stars, Rotation, Convective Boundaries, and Energy Conservation (2019, background): “Both cases show significant departures from the uniform period spacing ∆P ≈ 104 s predicted by asymptotic theory; these departures are caused by the abundance-gradient region, and therefore are an asteroseismic diagnostic of the star’s age (e.g., Miglio et al. 2008).”
- Asteroseismic measurement of surface-to-core rotation in a main-sequence A star, KIC 11145123 (2014, background): “As discussed by Miglio et al. (2008), c© 0000 RAS, MNRAS000, 000–000 the period spacing is modulated due to the presence of a steepvariation in the Brunt-Väisälä frequency caused by a change ithe gradient of the distribution of mean molecular weight.”
- Mixed modes in red-giant stars observed with CoRoT (2011, background): “We have also clear indication that mixed modes in red giants are sensitive to chemical composition gradients in the deep interior, as they ar in SPB andγ Doradus stars (Miglio et al. 2008).”