Transient Formation of Loops in the Core of an Active Region

TL;DR

This study investigates the formation of transient, multi-thermal loops in an active region's core using multi-wavelength solar observations, revealing their magnetic and thermal properties and suggesting magnetic reconnection as a formation mechanism.

Contribution

It provides detailed multi-wavelength analysis of transient loops, highlighting their multi-thermal nature and potential magnetic reconnection origin, advancing understanding of coronal plasma formation.

Findings

Transient loops are multi-thermal and observed across UV and EUV channels.

DEM analysis shows clumpy structure with high emission at specific temperatures.

Magnetic reconnection likely causes the transient loops.

Abstract

We study the formation of transient loops in the core of the AR 11890. For this purpose, we have used the observations recorded by the Atmospheric Imaging Assembly (AIA) and the Interface Region Imaging Spectrograph (IRIS). For photospheric field configuration, we have used the line-of-sight (LOS) magnetograms obtained from the Helioseismic and Magnetic Imager (HMI). The transient is simultaneously observed in all the UV and EUV channels of AIA and the three slit-jaw images from IRIS. The co-existence of the transient in all AIA and IRIS SJI channels suggests the transient's multi-thermal nature. The transient consists of short loops located at the base of the transient as well as longe loops. A differential emission measure (DEM) analysis shows that the transient has a clumpy structure. The highest emission observed at the base is within the temperature bin of $\log\, T = 6.65 - 6.95$. We observe the longer loops at a similar temperature, albeit very feeble. Using LOS magnetograms, we conclude that the magnetic reconnection may have caused the transient. Our observations further suggest that the physics of the formation of such transients may be similar to those of typical coronal jets, albeit in different topological configurations. Such multi-wavelength observations shed light on the formation of hot plasma in the solar corona and provide further essential constraints on modeling the thermodynamics of such transients.