Network Coronal Bright Points: Coronal Heating Concentrations Found in the Solar Magnetic Network

Abstract

We examine the magnetic origins of coronal heating in quiet regions by combining SOHO/EIT Fe XII coronal images and Kitt Peak magnetograms. Spatial filtering of the coronal images shows a network of enhanced structures on the scale of the magnetic network in quiet regions. Superposition of the filtered coronal images on maps of the magnetic network extracted from the magnetograms shows that the coronal network does indeed trace and stem from the magnetic network. Network coronal bright points, the brightest features in the network lanes, are found to have a highly significant (8 sigma above random chance) coincidence with polarity dividing lines (neutral lines) in the network, and are often at the feet of enhanced coronal structures that stem from the network and reach out over the cell interiors. These results indicate that, similar to the close linkage of neutral-line core fields with coronal heating in active regions, low-lying core fields encasing neutral lines in the magnetic network often drive noticeable coronal heating both within themselves (the network coronal bright points) and on more extended fields lines rooted around them. This behavior favors the possibility that active core fields in the network are the main drivers of the heating of the bulk of the quiet corona, on scales much larger than the network lanes and cells.