Oscillating light wall above a sunspot light bridge

Abstract

With the high tempo-spatial \emph{Interface Region Imaging Spectrograph} 1330 Å images, we find that many bright structures are rooted in the light bridge of NOAA 12192, forming a \emph{light wall}. The light wall is brighter than the surrounding areas, and the wall top is much brighter than the wall body. The New Vacuum Solar Telescope H$\alpha$ and the \emph{Solar Dynamics Observatory} 171 Å and 131 Å images are also used to study the light wall properties. In 1330 Å, 171 Å, and 131 Å, the top of the wall has a higher emission, while in the H$\alpha$ line, the wall top emission is very low. The wall body corresponds to bright areas in 1330 Å and dark areas in the other lines. The top of the light wall moves upward and downward successively, performing oscillations in height. The deprojected mean height, amplitude, oscillation velocity, and the dominant period are determined to be 3.6 Mm, 0.9 Mm, 15.4 km s${}^{-1}$, and 3.9 min, respectively. We interpret the oscillations of the light wall as the leakage of \emph{p}-modes from below the photosphere. The constant brightness enhancement of the wall top implies the existence of some kind of atmospheric heating, e.g., via the persistent small-scale reconnection or the magneto-acoustic waves. In another series of 1330 Å images, we find that the wall top in the upward motion phase is significantly brighter than in the downward phase. This kind of oscillations may be powered by the energy released due to intermittent impulsive magnetic reconnection.

8 pages, 5 figures; accepted for publication in ApJL

References in corpus (12)

• The Interface Region Imaging Spectrograph (IRIS)
• On Solving the Coronal Heating Problem
• Magnetic Structure of Sunspots
• The Confined X-class Flares of Solar Active Region 2192
• High-resolution Observations of the Shock Wave Behavior for Sunspot Oscillations with the Interface Region Imaging Spectrograph
• Magnetic reconnection between small-scale loops observed with the New Vacuum Solar Telescope
• Vigorous convection in a sunspot granular light bridge
• Multi-height observations of magnetoacoustic cut-off frequency in a sunspot atmosphere
• Propagating Disturbances in Coronal Loops: A Detailed Analysis of Propagation Speeds
• Dynamics of the solar atmosphere above a pore with a light bridge
• Oscillations in a sunspot with light bridges
• Three-minute wave enhancement in the solar photosphere

Cited by in corpus (25)

• Are IRIS bombs connected to Ellerman bombs?
• Frequently Occurring Reconnection Jets from Sunspot Light Bridges
• Abnormal oscillation modes in a waning light bridge
• Imaging and spectral study on the null point of a fan-spine structure during a solar flare
• Light Walls Around Sunspots Observed by the Interface Region Imaging Spectrograph
• Enhancement of a sunspot light wall with external disturbances
• Extending Counter-Streaming Motion from an Active Region Filament to Sunspot Light Bridge
• Signatures of magnetic reconnection at the footpoints of fan shape jets on a light bridge driven by photospheric convective motions
• A solar flare disturbing a light wall above a sunspot light bridge
• Dark structures in sunspot light bridges
• Observations of upward propagating waves in the transition region and corona above Sunspots
• Sunspot Light Walls Suppressed by Nearby Brightenings
• Sunspot penumbral filaments intruding into a light bridge and the resultant reconnection jets
• Magnetic connectivity between the light bridge and penumbra in a sunspot
• Transition region loops in the very late phase of flux-emergence in IRIS sit-and-stare observations
• Structure of sunspot light bridges in the chromosphere and transition region
• Dynamics in the transition region beneath active region upflows viewed by IRIS
• Light Bridges Can Suppress the Formation of Coronal Loops
• Small-scale Bright Blobs Ejected from a Sunspot Light Bridge
• Chromospheric recurrent jets in a sunspot group and their inter-granular origin
• Chromospheric plasma ejection above a pore
• Various Activities above Sunspot Light Bridges in IRIS Observations: Classification and Comparison
• Behaviour of oscillations in loop structures above active regions
• A new view of the solar interface region from the Interface Region Imaging Spectrograph (IRIS)
• Bidirectional Plasma Jets Driven by Magnetic Reconnection: Observations by GST and SDO