Analytical Models for Cross‐Correlation Signal in Time‐Distance Helioseismology

Analytical models for Cross-correlation signal in Time-Distance Helioseismology

In time-distance helioseismology, the time signals (Doppler shifts) at two points on the solar surface, separated by a fixed angular distance are crosscorrelated, and this leads to a wave packet signal. Accurately measuring the travel times of these wave packets is crucial for inferring the sub-surface properties in the Sun. The observed signal is quite noisy, and to improve the signal-tonoise ...

Helioseismology and Standard Solar Models

We present a systematical analysis of uncertainties in the helioseismological determination of quantities characterizing the solar structure. We discuss the effect of errors on the measured frequencies, the residual solar model dependence and the uncertainties of the inversion method. We find Y ph = 0.238 − 0.259, R b /R ⊙ = 0.708 − 0.714 and ρ b = (0.185 − 0.199) gr/cm 3 (the index b refers to...

Helioseismology, Solar Models and Neutrino Fluxes

We present our results concerning a systematical analysis of helioseismic implications on solar structure and neutrino production. We find Yph = 0.238 − 0.259, Rb/R⊙ = 0.708 − 0.714 and ρb = (0.185 − 0.199) gr/cm . In the interval 0.2 < R/R⊙ < 0.65, the quantity U = P/ρ is determined with and accuracy of ±5 ◦/◦◦ or better. At the solar center still one has remarkable accuracy, ∆U/U < 4%. We com...

Helioseismology challenges models of solar convection.

C onvection is the mechanism by which energy is transported through the outermost 30% of the sun (1). Solar turbulent convection is notoriously difficult to model across the entire convection zone, where the density spans many orders of magnitude. In PNAS, Hanasoge et al. (2) use recent helioseismic observations to derive stringent empirical constraints on the amplitude of large-scale convectiv...

Data Compression for Helioseismology