Evolutionary and Observational Properties of Red Giant Acoustic Glitch Signatures

Abstract While solar-like oscillations in red giants have been observed at massive scales by the Kepler mission, few features of these oscillation mode frequencies, other than their global properties, exploited for stellar characterization. The signatures acoustic glitches frequencies used studying main-sequence stars, but validity applying such techniques to evolved giants, particularly pertaining inclusion nonradial modes, has less well examined. Making use new theoretical developments, we characterize using π modes associated with giant models, and our procedure examine first time how properties He ii glitch—specifically its amplitude depth—vary over course evolution up branch, respect fundamental properties. We find that depths glitches, conjunction spectroscopic information, discriminate between first-ascent core-helium-burning phases. critically reexamine previous attempts constrain from (in particular dipole) giants. Finally, apply fitting data, evaluate robustness noise observational systematics.