Research Projects

Solar flares are explosive manifestations of magnetic energy release in the solar corona, producing rapid heating, particle acceleration, and radiative output across the electromagnetic spectrum. Despite the success of the “Standard” flare model, key questions remain about how flare-accelerated particles transport energy to the lower atmosphere and how that energy is deposited and radiated, particularly in the chromosphere. Limitations in simultaneous, spatially resolved, multi-wavelength observations have restricted our ability to diagnose energy deposition pathways and validate chromospheric heating models. Coordinated observations from the Solar Ultraviolet Imaging Telescope (SUIT) aboard Aditya-L1, the X-ray Solar Monitor (XSM) on Chandrayaan-2, the Spectrometer/Telescope for Imaging X-rays (STIX) on Solar Or- biter, and the High Energy L1 Orbiting X-ray Spectrometer (HEL1OS) on Aditya-L1 together enable, for the first time, spatially and temporally resolved diagnostics of chromospheric and coronal flare responses. This project leverages SUIT’s narrowband imaging in the Mg II h & k lines and adjacent continua, soft X-ray spec- tra from XSM, hard X-ray imaging and spectroscopy from STIX, and hard X-ray spectroscopy from HEL1OS. These observations will be complemented by 1D non-Local Thermal Equilibrium (non-LTE) radiative hydro- dynamic modeling. The central scientific objective is to determine how energy deposited by flare-accelerated electrons manifests in near-ultraviolet enhancements observed in Mg II wings and continua. We hypothesize that these enhancements result not only from photospheric backwarming but also from direct chromospheric heating, potentially involv- ing metallic line emission or Balmer continuum processes. This will be tested using flare events spanning a range of classes and disk positions, starting with the X6.3-class flare on February 22, 2024. The project will: (1) quantify Mg II wing and continuum enhancements using SUIT; (2) assess thermal evolution and abundance changes with XSM; (3) derive timing and energetics of non-thermal electrons from STIX; (4) run 1D radiative hydrodynamic simulations using RADYN; and (5) synthesise spectral profiles for comparison with observations. This approach will yield height–time heating profiles and constrain the atmospheric response to energy deposition. Expected outcomes include the first spatially resolved dataset of Mg II wing and continuum flare enhancements, physical interpretation of these features, and constraints on energy transport models through multi-instrument synergy. These results will improve our understanding of flare energy deposition, support forward modeling for future missions, and offer key diagnostics for ultraviolet flare interpretation. Ultimately, this work will advance heliophysics and space weather science by clarifying how magnetic reconnection, particle acceleration, and atmospheric radiation are coupled during solar flares.