EUV flickering of solar coronal loops: a new diagnostic of coronal heating

Abstract

A previous work of ours found the best agreement between EUV light curves observed in an active region core (with evidence of super-hot plasma) and those predicted from a model with a random combination of many pulse-heated strands with a power-law energy distribution. We extend that work by including spatially resolved strand modeling and by studying the evolution of emission along the loops in the EUV 94 A and 335 A channels of the Atmospheric Imaging Assembly on-board the Solar Dynamics Observatory. Using the best parameters of the previous work as the input of the present one, we find that the amplitude of the random fluctuations driven by the random heat pulses increases from the bottom to the top of the loop in the 94 A channel and, viceversa, from the top to the bottom in the 335 A channel. This prediction is confirmed by the observation of a set of aligned neighbouring pixels along a bright arc of an active region core. Maps of pixel fluctuations may therefore provide easy diagnostics of nano-flaring regions.

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Cited by in corpus (9)

• Waves in the lower solar atmosphere: the dawn of next-generation solar telescopes
• Non-Equilibrium Processes in the Solar Corona, Transition Region, Flares, and Solar Wind \textit{(Invited Review)}
• Investigating the response of loop plasma to nanoflare heating using RADYN simulations
• Inference of Heating Properties from "Hot" Non-flaring Plasmas in Active Region Cores I. Single Nanoflares
• 3D MHD modeling of twisted coronal loops
• Plasma sloshing in pulse-heated solar and stellar coronal loops
• Statistical Signatures of Nanoflare Activity. I. Monte Carlo Simulations and Parameter-space Exploration
• Non-equilibrium ionization by a periodic electron beam II. Synthetic Si IV and O IV transition region spectra
• Morphological evidence for nanoflares heating warm loops in the solar corona