24 citations · 43 across the 7 of their papers we have counts for
7 papers
Magnetic field fluctuations in the shocked umbral chromosphere
T. Felipe, S. J. González Manrique, C. R. Sangeetha +1
Several studies have reported magnetic field fluctuations associated with umbral shock waves. We aim to study the properties and origin of magnetic field fluctuations in the umbral…
Limitations of the Ca II 8542 Å line for the determination of magnetic field oscillations
T. Felipe, H. Socas Navarro, C. R. Sangeetha +1
Chromospheric umbral oscillations produce periodic brightenings in the core of some spectral lines, known as umbral flashes. They are also accompanied by fluctuations in velocity,…
Chromospheric resonances above sunspots and potential seismological applications
T. Felipe, C. Kuckein, S. J. González Manrique +2
Oscillations in sunspot umbrae exhibit remarkable differences between the photosphere and chromosphere. We evaluate two competing scenarios proposed for explaining those observatio…
Numerical determination of the cutoff frequency in solar models
T. Felipe, C. R. Sangeetha
In stratified atmospheres, acoustic waves can only propagate if their frequency is above the cutoff value. Different theories provide different cutoff values. We developed an alter…
Signatures of Untwisting Magnetic Field in a Small Emerging Bipole in the Solar Photosphere
C. R. Sangeetha, Durgesh Tripathi, S. P. Rajaguru
We perform a study of fluid motions and its temporal evolution in and around a small bipolar emerging flux region using observations made by the Helioseismic and Magnetic Imager (H…
Magnetic fields and low-frequency acoustic wave-energy supply to the solar chromosphere
S. P. Rajaguru, C. R. Sangeetha, Durgesh Tripathi
The problem of solar chromospheric heating remains a challenging one with wider implications for stellar physics. Several studies in the recent past have shown that small-scale inc…