Bibcode
Mathur, S.; Eff-Darwich, A.; García, R. A.; Turck-Chièze, S.
Bibliographical reference
Astronomy and Astrophysics, Volume 484, Issue 2, 2008, pp.517-522
Advertised on:
6
2008
Journal
Citations
68
Refereed citations
44
Description
Context: The dynamics of the solar core cannot be properly constrained
through the analysis of acoustic oscillation modes. Gravity modes (g
modes) are necessary to understand the structure and dynamics of the
deepest layers of the Sun. Through recent progress on the observation of
these modes - both individually and collectively - new information is
available to contribute to inferring the rotation profile inside the
nuclear burning core. Aims: We aim to see the sensitivity of
gravity modes to the rotation of the solar core. We analyze the
influence of adding the splitting of one and several g modes to the data
sets used in helioseismic numerical inversions. We look for constraints
on the uncertainties required in the observations to improve the derived
core rotation profile. Methods: We compute three artificial sets
of splittings derived for three rotation profiles: a rigid profile taken
as a reference; a step-like profile and a smoother profile with higher
rates in the core. We compute inversions based on regularized
least-squares methodology (RLS) for both artificial data with real error
bars and real data. Several sets of data are used: first, we invert only
acoustic modes (p modes), then we add one and several g modes to which
different values of observational uncertainties (75 and 7.5 nHz) are
attributed. For the real data, we include g-mode candidate, ℓ=2,
n=-3 with several splittings and associated uncertainties. Results: We show that the introduction of one g mode in artificial
data improves the rate in the solar core and gives an idea of the
tendency of the rotation profile. The addition of more g modes lends
greater accuracy to the inversions and stabilizes them. The inversion of
real data with the g-mode candidate gives a rotation profile that
remains unchanged down to 0.2 R&sun;, whatever value of
splitting we attribute to the g mode.
Related projects
Helio and Astero-Seismology and Exoplanets Search
The principal objectives of this project are: 1) to study the structure and dynamics of the solar interior, 2) to extend this study to other stars, 3) to search for extrasolar planets using photometric methods (primarily by transits of their host stars) and their characterization (using radial velocity information) and 4) the study of the planetary
Savita
Mathur