Abstract Details


Name: Srikar Paavan Tadepalli
Affiliation: ISRO
Conference ID: TVS202510291
Title: Evolution of Quasi-Periodic Pulsations in Solar Flares: A multi-wavelength perspective
Authors and Co-Authors: Abhishekh Kumar Srivastava, Sankarasubramanian K
Abstract Type: Contributory Presentation
Abstract: Quasi-Periodic Pulsations (QPPs) are a well-known feature of solar flares and provide valuable insight into the plasma processes that govern energy release, particle acceleration, and transport. While many studies have demonstrated their occurrence, it has also become clear that QPPs are often non-stationary, with their periods and amplitudes evolving in time. Despite this, a unified picture of how QPPs change across the entire life cycle of a flare remains incomplete.In this work, we aim to follow the temporal evolution of QPPs through the pre-flare, impulsive, and decay phases. The analysis focuses on a selected set of well-observed events, with the goal of tracking how key oscillatory parameters ,particularly the period and amplitude, vary as the flare progresses. We make use of X-ray data from the spectrometers onboard Aditya-L1, complemented by observations at other wavelengths, to separate thermal pulsations in soft X-rays during the pre-flare and decay stages from non-thermal pulsations in hard X-rays that dominate the impulsive phase.A key question we address is whether QPPs observed before or after the impulsive phase bear a causal relationship to those seen during the flare’s peak. For example, could oscillatory activity in the pre-flare stage act as a precursor for the main energy release? By combining X-ray diagnostics with complementary measurements from other wavelengths, we attempt to map the continuity (or lack thereof) of QPP signatures across flare phases. Through this approach, we aim to place observational constraints on the physical mechanisms that generate QPPs, with particular emphasis on oscillatory reconnection, wave–particle interactions, and energy transport in flare loops.