Computational local helioseismology in the frequency domain
Chris Hanson (Max-Planck-Institut für Sonnensystemforschung), The MPS-INRIA Collaboration (Max-Planck-Institut für Sonnensystemforschung and INRIA Bordeaux), et al.

Forward problems in local helioseismology have thus far been addressed in a semi-analytical fashion using the Born approximation and normal mode expansions. However, it has proven difficult to take into account geometrical and instrumental effects. To avoid these difficulties we employ a numerical method to determine the impulse response of a solar model in a 2.5D geometry. Solving the wave equation in the frequency domain avoids the difficulties (instabilities) faced in the time domain. This framework is flexible, computationally efficient, and produces solar-like power spectrum and cross-covariance that match accurately with observations, including the high-frequency continuous spectrum. Additionally, we present accurate travel-time sensitivity kernels for perturbations to the solar medium which hint at the promising potential of this framework in future forward and inversion problems.