Heating of Flare Loops With Observationally Constrained Heating Functions

TL;DR

This paper uses high-resolution observations of a solar flare to empirically derive heating functions for individual flare loops, improving understanding of the heating process and providing constraints for coronal heating models.

Contribution

It introduces a method to observationally infer heating functions for multiple flare loops using spatially resolved UV light curves, advancing flare modeling techniques.

Findings

Magnetic reconnection and loop formation continue for over two hours.

Individual footpoints brighten instantaneously and decay over 30 minutes.

The derived heating functions match observed X-ray and EUV fluxes.

Abstract

We analyze high cadence high resolution observations of a C3.2 flare obtained by AIA/SDO on August 1, 2010. The flare is a long duration event with soft X-ray and EUV radiation lasting for over four hours. Analysis suggests that magnetic reconnection and formation of new loops continue for more than two hours. Furthermore, the UV 1600\AA\ observations show that each of the individual pixels at the feet of flare loops is brightened instantaneously with a timescale of a few minutes, and decays over a much longer timescale of more than 30 minutes. We use these spatially resolved UV light curves during the rise phase to construct empirical heating functions for individual flare loops, and model heating of coronal plasmas in these loops. The total coronal radiation of these flare loops are compared with soft X-ray and EUV radiation fluxes measured by GOES and AIA. This study presents a method to observationally infer heating functions in numerous flare loops that are formed and heated sequentially by reconnection throughout the flare, and provides a very useful constraint to coronal heating models.