Astronomy and Astrophysics – Astrophysics
Scientific paper
Feb 2011
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2011a%26a...526a.137d&link_type=abstract
Astronomy and Astrophysics, Volume 526, id.A137
Astronomy and Astrophysics
Astrophysics
9
Sun: Corona, Sun: Radio Radiation, Techniques: Spectroscopic
Scientific paper
We propose a unified interpretation for persistent coronal outflows and metric radio noise storms, two phenomena typically observed in association with quiescent solar active regions. Our interpretation is based on multi-wavelength observations of two such regions as they crossed the meridian in May and July 2007. For both regions, we observe a persistent pattern of blue-shifted coronal emission in high-temperature lines with Hinode/EIS, and a radio noise storm with the Nançay Radioheliograph. The observations are supplemented by potential and linear force-free extrapolations of the photospheric magnetic field over large computational boxes, and by a detailed analysis of the coronal magnetic field topology. We find true separatrices in the coronal field and null points high in the corona, which are preferential locations for magnetic reconnection and electron acceleration. We suggest that the continuous growth of active regions maintains a steady reconnection across the separatrices at the null point. This interchange reconnection occurs between closed, high-density loops in the core of the active region and neighbouring open, low-density flux tubes. Thus, the reconnection creates strong pressure imbalances which are the main drivers of plasma upflows. Furthermore, the acceleration of low-energy electrons in the interchange reconnection region sustains the radio noise storm in the closed loop areas, as well as weak type III emission along the open field lines. For both active regions studied, we find a remarkable agreement between the observed places of persistent coronal outflows and radio noise storms with their locations as predicted by our interpretation.
Aulanier Guillaume
Del Zanna Giulio
Klein Karl-Ludwig
Torok Tibor
No associations
LandOfFree
A single picture for solar coronal outflows and radio noise storms does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with A single picture for solar coronal outflows and radio noise storms, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and A single picture for solar coronal outflows and radio noise storms will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1363847