Facial reconstruction

Search LJMU Research Online

Browse Repository | Browse E-Theses

The Aarhus red giants challenge: II. Stellar oscillations in the red giant branch phase

Christensen-Dalsgaard, J, Silva Aguirre, V, Cassisi, S, Miller Bertolami, M, Serenelli, A, Stello, D, Weiss, A, Angelou, G, Jiang, C, Lebreton, Y, Spada, F, Bellinger, EP, Deheuvels, S, Ouazzani, RM, Pietrinferni, A, Mosumgaard, JR, Townsend, RHD, Battich, T, Bossini, D, Constantino, T , Eggenberger, P, Hekker, S, Mazumdar, A, Miglio, A, Nielsen, KB and Salaris, M (2020) The Aarhus red giants challenge: II. Stellar oscillations in the red giant branch phase. Astronomy and Astrophysics, 635. ISSN 0004-6361

[img]
Preview
Text
The Aarhus red giants challenge.pdf - Published Version

Download (2MB) | Preview

Abstract

Contact. The large quantity of high-quality asteroseismic data that have been obtained from space-based photometric missions and the accuracy of the resulting frequencies motivate a careful consideration of the accuracy of computed oscillation frequencies of stellar models, when applied as diagnostics of the model properties. Aims. Based on models of red-giant stars that have been independently calculated using different stellar evolution codes, we investigate the extent to which the differences in the model calculation affect the model oscillation frequencies and other asteroseismic diagnostics. Methods. For each of the models, which cover four different masses and different evolution stages on the red-giant branch, we computed full sets of low-degree oscillation frequencies using a single pulsation code and, from these frequencies, typical asteroseismic diagnostics. In addition, we carried out preliminary analyses to relate differences in the oscillation properties to the corresponding model differences. Results. In general, the differences in asteroseismic properties between the different models greatly exceed the observational precision of these properties. This is particularly true for the nonradial modes whose mixed acoustic and gravity-wave character makes them sensitive to the structure of the deep stellar interior and, hence, to details of their evolution. In some cases, identifying these differences led to improvements in the final models presented here and in Paper I; here we illustrate particular examples of this. Conclusions. Further improvements in stellar modelling are required in order fully to utilise the observational accuracy to probe intrinsic limitations in the modelling and improve our understanding of stellar internal physics. However, our analysis of the frequency differences and their relation to stellar internal properties provides a striking illustration of the potential, in particular, of the mixed modes of red-giant stars for the diagnostics of stellar interiors. © ESO 2020.

Item Type: Article
Uncontrolled Keywords: 0201 Astronomical and Space Sciences
Subjects: Q Science > QB Astronomy
Q Science > QC Physics
Divisions: Astrophysics Research Institute
Publisher: EDP Sciences
Date Deposited: 20 Apr 2020 09:57
Last Modified: 20 Apr 2020 10:00
DOI or Identification number: 10.1051/0004-6361/201936766
URI: http://researchonline.ljmu.ac.uk/id/eprint/12762

Actions (login required)

View Item View Item