What makes the limb flares detectable in visible lights, hydrogen recombination or Thomson scattering?
Through analyzing a suite of space- and ground-based observations, the authors report that above sunspots, helioseismic waves of different frequencies are able to channel up through the chromosphere and transition region into corona. General pictures of how the waves make into corona are also shown.
We have generated a dataset of emerging active regions (EARs) observed by SDO/HMI that is specifically suitable for helioseismic analysis. Using this dataset we show that, on average the bipoles have a symmetric the east-west velocity relative to differential rotation.
We observed magnetoacoustic waves propagating along the magnetic field lines of a sunspot. Based on the wave periods and atmospheric characteristics, we reconstructed the magnetic field topology of the sunspot.
By synthesizing the results of photospheric field change indicated by HMI observations and coronal field variation suggested by the NLFFF modeling, we study the flare-related 3D magnetic restructuring and find it consistent with the coronal implosion scenario in the low solar atmosphere.