Line broadening of EUV lines across the Solar limb: A spicule contribution?
Doyle, J. G.; Madjarska, M. S.; Xia, L. D.; Giannikakis, J.
United Kingdom, Greece, China, Belgium
Abstract
Spectral lines formed in the solar transition region show an increase in the line width, peaking at ≈10 000 km above the limb. Looking at a region off-limb with no obvious spicules, the non-spicule region has a significantly smaller line width above 6000 km compared those taken in a spicule region. We suggest that this increase in line broadening is not due to small scale random motions but rather to unresolved line shifts due to spicules and/or macro-spicules activity.