114 citations · 555 across the 34 of their papers we have counts for
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Separating surface magnetic effects in sunspot seismology: new time-distance helioseismic diagnostics
S. P. Rajaguru
Time-distance helioseismic measurements in surface- and deep-focus geometries for wave-paths that distinguish surface magnetic contributions from those due to deeper perturbations…
Impact of Locally Suppressed Wave sources on helioseismic travel times
S. M. Hanasoge, S. Couvidat, S. P. Rajaguru +1
Wave travel-time shifts in the vicinity of sunspots are typically interpreted as arising predominantly from magnetic fields, flows, and local changes in sound speed. We show here t…
Contamination by Surface Effects of Time-distance Helioseismic Inversions for Sound Speed Beneath Sunspots
S. Couvidat, S. P. Rajaguru
Using Doppler velocity data from the SOI/MDI instrument onboard the SoHO spacecraft, we do time-distance helioseismic inversions for sound-speed perturbations beneath 16 sunspots o…
Radiative transfer effects on Doppler measurements as sources of surface effects in sunspot seismology
S. P. Rajaguru, K. Sankarasubramanian, R. Wachter +1
We show that the use of Doppler shifts of Zeeman sensitive spectral lines to observe wavesn in sunspots is subject to measurement specific phase shifts arising from, (i) altered he…
Sensitivity of time-distance helioseismic measurements to spatial variation of oscillation amplitudes I. Observations and a numerical model
S. P. Rajaguru, A. C. Birch, T. L. Duvall +2
It is well known that the observed amplitude of solar oscillations is lower in sunspots than in quiet regions of the Sun. We show that this local reduction in oscillation amplitude…
Convective intensification of magnetic flux tubes in stellar photospheres
S. P. Rajaguru, R. L. Kurucz, S. S. Hasan
The convective collapse of thin magnetic flux tubes in the photospheres of sun-like stars is investigated using realistic models of the superadiabatic upper convection zone layers…