| Name: AKASH BAIRAGI |
| Affiliation: IIT(BHU) |
| Conference ID: ASI2026_526 |
| Title: Interaction of EUV-wave Like Perturbations with the Localized Coronal Null and Occurrence of Fast to Alfvén Wave Mode Conversion |
| Abstract Type: Poster |
| Abstract Category: Sun, Solar System, Exoplanets, and Astrobiology |
| Author(s) and Co-Author(s) with Affiliation: Akash Bairagi(IIT(BHU), Varanasi - 221005, India), Abhishekh Kumar Srivastava(IIT(BHU), Varanasi - 221005, India), Teimuraz Zaqarashvili(Institute of Physics University of Graz, A-8010 Graz, Austria), Philippe A. Bourdin(Institute of Physics University of Graz, A-8010 Graz, Austria), Sripan Mondal(IIT(BHU), Varanasi - 221005, India), Astrid Veronig(Institute of Physics University of Graz, A-8010 Graz, Austria) |
| Abstract: The Sun's atmosphere possesses different kinds of MHD wave modes and their mutual conversion is possible under appropriate plasma and magnetic-field conditions. The fast and slow mode waves are ubiquitously observed in the Sun’s corona but the Alfvén modes are very difficult to observe due to their incompressible nature. Owing to their properties, Alfvén mode is believed to be one of the energy sources for the solar corona and this mode can even be generated in the vicinity of the equipartition layer (Vs≈Va) through the interaction of fast mode with the magnetic null. In this present work, we have performed 2.5D resistive MHD numerical simulation of Alfvén mode generation through the mode conversion when an EUV wave-like perturbation, akin of the fast magnetoacoustic waves, interacts with the localized magnetic null. As the fast mode front interacts with the null, some parts of this wave-front get refracted, while some other part is trapped at the null region. Subsequently, the out of the plane velocity (i.e., Vz) and magnetic field fluctuations (i.e., Bz) have been seen propagating with local Alfvén speed along the separatrices at one side of the null region. In the synthetic SDO/AIA observations, no intensity fluctuations have been evident. Our results demonstrate that given the appropriate physical conditions at the coronal null, when EUV wave-like perturbations are incident, due to mode conversion Alfvén waves can excite further carrying substantial momentum and energy flux. |
