# Impulsive coronal heating from large-scale magnetic rearrangements: from IRIS to SDO/AIA

## TL;DR

This paper links IRIS-observed transition region brightenings with hot coronal loops, highlighting impulsive heating driven by magnetic rearrangements and the potential role of non-thermal electrons in active regions.

## Contribution

It demonstrates the connection between IRIS bright spots and hot coronal loops, emphasizing impulsive heating and magnetic interactions, and suggests non-thermal electrons are significant in coronal heating.

## Key findings

- IRIS bright spots are footpoints of hot, transient coronal loops.
- Magnetic interactions cause impulsive heating in these loops.
- Non-thermal electrons may play a key role in heating processes.

## Abstract

The Interface Region Imaging Spectrograph (IRIS) has observed bright spots at the transition region footpoints associated with heating in the overlying loops, as observed by coronal imagers. Some of these brightenings show significant blueshifts in the Si iv line at 1402.77 A (logT[K] = 4.9). Such blueshifts cannot be reproduced by coronal loop models assuming heating by thermal conduction only, but are consistent with electron beam heating, highlighting for the first time the possible importance of non-thermal electrons in the heating of non-flaring active regions. Here we report on the coronal counterparts of these brightenings observed in the hot channels of the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory. We show that the IRIS bright spots are the footpoints of very hot and transient coronal loops which clearly experience strong magnetic interactions and rearrangements, thus confirming the impulsive nature of the heating and providing important constraints for their physical interpretation.