Statistics of Local Seismic Emission from the Solar Granulation

TL;DR

This study uses computational seismic holography on high-frequency helioseismic data to identify sources of seismic emission in the solar granulation, revealing unexpected high emission from bright regions.

Contribution

It provides new insights into the spatial distribution of seismic emission in the solar granulation, highlighting unexpected high emission from regions with brightness above 104% of the mean.

Findings

Seismic emission is greatest at granule edges.

Regions with brightness 95-100% of mean emit 2.5 times more seismic energy.

High seismic emission also occurs in regions brighter than 104% of the mean.

Abstract

We apply computational seismic holography to high-frequency helioseismic observations of the quiet Sun from SDO/HMI to locate predominant sources of seismic emission with respect to the structure of the solar granulation. The regions of greatest seismic emission are the edges of photospheric granules. Seismic emission from regions whose continuum brightnesses are 95-100% of the mean, as resolved by HMI, are about 2.5 times as emissive as regions whose brightnesses are 100-104% of the mean. The greater seismic emissivity from regions whose brightnesses are somewhat less than the mean is roughly in line with expectations from an understanding that attributes most seismic emission to cool plumes plummeting from the edges of granules. However, seismic emission from regions whose continuum brightnesses significantly exceed 104% of the mean is also remarkably high. This unexpected feature of high-frequency seismic emission from the solar granulation begs to be understood.