English

Direct observations of different sunspot waves influenced by umbral flashes

Solar and Stellar Astrophysics 2017-12-13 v2

Abstract

We report the simultaneous presence of chromospheric umbral flashes and associated umbral waves, and propagating coronal disturbances, in a sunspot and related active region. We have analyzed time-distance maps obtained using the observations from Atmospheric Imaging Assembly (AIA) on-board Solar Dynamics Observatory (SDO). These maps show the simultaneous occurrence of different sunspot oscillation and waves such as umbral flashes, umbral waves, and coronal waves. Analysis of the original light curves, i.e., without implementing any Fourier filtering on them, show that the amplitudes of different sunspot waves observed at different atmospheric layers change in synchronization with the light curves obtained from the umbral flash region, thus demonstrating that these oscillations are modulated by umbral flashes. This study provides the first observational evidence of the influence of sunspot oscillations within the umbra on other sunspot waves extending up to the corona. The properties of these waves and oscillations can be utilized to study the inherent magnetic coupling among different layers of the solar atmosphere above sunspots.

Keywords

Cite

@article{arxiv.1710.08438,
  title  = {Direct observations of different sunspot waves influenced by umbral flashes},
  author = {Aishawnnya Sharma and G. R. Gupta and Durgesh Tripathi and V. Kashyap and Amit Pathak},
  journal= {arXiv preprint arXiv:1710.08438},
  year   = {2017}
}

Comments

10 pages, 11 figures. Published in the ApJ