Propagating Linear Waves in Convectively Unstable Stellar Models: a Perturbative Approach

Abstract

Linear time-domain simulations of acoustic oscillations are unstable in the stellar convection zone. To overcome this problem it is customary to compute the oscillations of a stabilized background stellar model. The stabilization, however, affects the result. Here we propose to use a perturbative approach (running the simulation twice) to approximately recover the acoustic wave field, while preserving seismic reciprocity. To test the method we considered a 1D standard solar model. We found that the mode frequencies of the (unstable) standard solar model are well approximated by the perturbative approach within $1\mu$Hz for low-degree modes with frequencies near $3\mu$Hz. We also show that the perturbative approach is appropriate for correcting rotational-frequency kernels. Finally, we comment that the method can be generalized to wave propagation in 3D magnetized stellar interiors because the magnetic fields have stabilizing effects on convection.

14 pages. Published online in Solar Physics, available at http://link.springer.com/article/10.1007/s11207-013-0457-7

References in corpus (4)

• ADIPLS -- the Aarhus adiabatic oscillation package
• ASTEC -- the Aarhus STellar Evolution Code
• SLiM: a code for the simulation of wave propagation through an inhomogeneous, magnetised solar atmosphere
• Validating Time-Distance Far-side Imaging of Solar Active Regions through Numerical Simulations

Cited by in corpus (5)

• Computational helioseismology in the frequency domain: acoustic waves in axisymmetric solar models with flows
• Helioseismic Modeling of Background Flows
• Forward Modeling Helioseismic Signatures of One- and Two-cell Meridional Circulation
• Simulating acoustic waves in spotted stars
• Asteroseismic Signature of a Large Active Region