Velocity-intensity asymmetry reversal of solar radial p-modes
| Autor: | Reza Samadi, C. Barban, J. Philidet, Hans-Günter Ludwig, Kevin Belkacem |
|---|---|
| Přispěvatelé: | Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Galaxies, Etoiles, Physique, Instrumentation (GEPI), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Zentrum für Astronomie der Universität Heidelberg (ZAH), Universität Heidelberg [Heidelberg] |
| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
010504 meteorology & atmospheric sciences
media_common.quotation_subject FOS: Physical sciences Astrophysics 01 natural sciences Asymmetry Spectral line methods: analytical Radiative flux Quality (physics) 0103 physical sciences stars: atmospheres Sun: oscillations 010303 astronomy & astrophysics Solar and Stellar Astrophysics (astro-ph.SR) 0105 earth and related environmental sciences Line (formation) media_common Sun: helioseismology Physics Spectral density Astronomy and Astrophysics stars: solar-type Intensity (physics) Stars Astrophysics - Solar and Stellar Astrophysics Space and Planetary Science [SDU]Sciences of the Universe [physics] stars: oscillations [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph] |
| Zdroj: | Astronomy and Astrophysics-A&A Astronomy and Astrophysics-A&A, EDP Sciences, 2020, 644, pp.A171. ⟨10.1051/0004-6361/202038222⟩ |
| ISSN: | 0004-6361 |
| DOI: | 10.1051/0004-6361/202038222⟩ |
| Popis: | The development of space-borne missions has significantly improved the quality of the measured spectra of solar-like oscillators. Their $p$-mode line profiles can now be resolved, and the asymmetries inferred for a variety of stars other than the Sun. However, it has been known for a long time that the asymmetries of solar $p$-modes are reversed between the velocity and the intensity spectra. Understanding the origin of this reversal is necessary in order to use asymmetries as a tool for seismic diagnosis. For stars other than the Sun, only the intensity power spectrum is sufficiently resolved to allow for an estimation of mode asymmetries. We recently developed an approach designed to model and predict these asymmetries in the velocity power spectrum of the Sun and to successfully compare them to their observationally derived counterparts. In this paper we expand our model and predict the asymmetries featured in the intensity power spectrum. We find that the shape of the mode line profiles in intensity is largely dependent on how the oscillation-induced variations of the radiative flux are treated, and that modelling it realistically is crucial to understanding asymmetry reversal. Perturbing a solar-calibrated grey atmosphere model, and adopting the quasi-adiabatic framework as a first step, we reproduce the asymmetries observed in the solar intensity spectrum for low-frequency modes. We conclude that, unlike previously thought, it is not necessary to invoke an additional mechanism (e.g. non-adiabatic effects, coherent non-resonant background signal) to explain asymmetry reversal. This additional mechanism is necessary, however, to explain asymmetry reversal for higher-order modes. Comment: 9 pages, 4 figures. Accepted for publication in A&A |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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