Search for photospheric footpoints of quiet Sun transition region loops

TL;DR

This study investigates the potential connection between photospheric bright points and quiet Sun transition region loops, suggesting BPs may serve as their footpoints but without definitive one-to-one identification.

Contribution

It introduces a novel approach using G-band bright points as proxies to locate photospheric footpoints of TR loops, addressing previous observational limitations.

Findings

Photospheric BPs are associated with bright TR structures.

BPs tend to avoid the brightest parts of TR loops.

TR explosive events are not clearly linked to BPs.

Abstract

CONTEXT:The footpoints of quiet Sun Transition Region (TR) loops do not seem to coincide with the photospheric magnetic structures appearing in traditional low-sensitivity magnetograms. AIMS: To look for the so-far unidentified photospheric footpoints of TR loops using G-band bright points (BPs) as proxies for photospheric magnetic field concentrations. METHODS: Comparison of TR measurements with SoHO/SUMER and photospheric magnetic field observations obtained with the Dutch Open Telescope. RESULTS: Photospheric BPs are associated with bright TR structures, but they seem to avoid the brightest parts of the structure. BPs appear in regions that are globally redshifted, but they avoid extreme velocities. TR explosive events are not clearly associated with BPs. CONCLUSIONS: The observations are not inconsistent with the BPs being footpoints of TR loops, although we have not succeeded to uniquely identify particular BPs with specific TR loops.