# Sunspot Light Walls Suppressed by Nearby Brightenings

**Authors:** Shuhong Yang, Jun Zhang, Robertus Erd\'elyi, Yijun Hou, Xiaohong Li,, Limei Yan

arXiv: 1706.07158 · 2017-07-19

## TL;DR

This study investigates how nearby brightenings suppress sunspot light walls, showing significant decay in their oscillation and visibility, likely due to magnetic reconnection or suppression of oscillation drivers.

## Contribution

It provides observational evidence that nearby brightenings can suppress sunspot light walls, proposing magnetic reconnection and oscillation suppression as possible mechanisms.

## Key findings

- Light walls decay after adjacent brightenings appear.
- Oscillation amplitude and height decrease significantly.
- Part of the light wall becomes invisible after brightening.

## Abstract

Light walls, as ensembles of oscillating bright structures rooted in sunspot light bridges, have not been well studied, although they are important for understanding sunspot properties. Using the Interface Region Imaging Spectrograph and Solar Dynamics Observatory observations, here we study the evolution of two oscillating light walls each within its own active region (AR). The emission of each light wall decays greatly after the appearance of adjacent brightenings. For the first light wall, rooted within AR 12565, the average height, amplitude, and oscillation period significantly decrease from 3.5 Mm, 1.7 Mm, and 8.5 min to 1.6 Mm, 0.4 Mm, and 3.0 min, respectively. For the second light wall, rooted within AR 12597, the mean height, amplitude, and oscillation period of the light wall decrease from 2.1 Mm, 0.5 Mm, and 3.0 min to 1.5 Mm, 0.2 Mm, and 2.1 min, respectively. Particularly, a part of the second light wall becomes even invisible after the influence of nearby brightening. These results reveal that the light walls are suppressed by nearby brightenings. Considering the complex magnetic topology in light bridges, we conjecture that the fading of light walls may be caused by a drop in the magnetic pressure, where flux is cancelled by magnetic reconnection at the site of the nearby brightening. Another hypothesis is that the wall fading is due to the suppression of driver source (p-mode oscillation), resulting from the nearby avalanche of downward particles along reconnected brightening loops.

## Full text

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## Figures

5 figures with captions in the complete paper: https://tomesphere.com/paper/1706.07158/full.md

## References

27 references — full list in the complete paper: https://tomesphere.com/paper/1706.07158/full.md

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Source: https://tomesphere.com/paper/1706.07158