Light Walls Around Sunspots Observed by the Interface Region Imaging Spectrograph

TL;DR

This study uses high-resolution IRIS data to identify and analyze light walls around sunspots, revealing their multi-layered, multi-thermal nature and occurrence along magnetic neutral lines in active regions.

Contribution

First detection of light walls near umbral-penumbral boundaries and along neutral lines, expanding understanding of their occurrence beyond light bridges.

Findings

Light walls are present around sunspots and above light bridges.

New observations show light walls near umbral-penumbral boundaries.

Light walls are multi-layered and multi-thermal structures along magnetic neutral lines.

Abstract

The Interface Region Imaging Spectrograph (IRIS) mission provides high-resolution observations of the chromosphere and transition region. We try to determine whether the light walls exist somewhere else in active regions besides light bridges. Employing half-year high tempo-spatial data from the IRIS, we find lots of light walls either around sunspots or above light bridges. For the first time, we report one light wall near an umbral-penumbral boundary and another along a neutral line between two small sunspots. These new observations reveal that these light walls are multi-layer and multi-thermal structures which occur along magnetic neutral lines in active regions.