Magnetic structure and flows in coronal prominence cavities
Abstract
Prominence cavities provide deep insight into the storage and release of magnetic energy in the solar corona. Recent studies have yielded a variety of observations that provide new constraints on models of prominences, cavities, and coronal mass ejections. In particular, a survey of SDO/AIA extreme-ultraviolet cavities has demonstrated that a tear-shaped morphology is a predictor of impending eruption, indicating that a change in topology may play a role in their destabilization. Other studies utilizing extreme-ultraviolet and infrared observations have shown both circulating plane-of-sky flows and a "bulls-eye" pattern in line-of-sight flows within cavities, indicating a central magnetic axis. A comparison of coronal flows within the cavity and flows associated with the embedded prominence demonstrate both spatial and temporal correlations, indicating they are both magnetically and thermodynamically connected. Finally, coronal magnetometric observations show a characteristic "rabbit-head" signature in linear polarization within polar-crown-prominence cavities, indicating twisted or sheared magnetic field at the heart of the cavity. All of these observations lend credence to the model of the cavity as a magnetic flux rope: both as a long-lived MHD equilibrium state and as a key component in the ultimate destabilization and eruption of coronal mass ejections.
- Publication:
-
AGU Spring Meeting Abstracts
- Pub Date:
- May 2013
- Bibcode:
- 2013AGUSMSH23B..04G
- Keywords:
-
- 7509 SOLAR PHYSICS;
- ASTROPHYSICS;
- AND ASTRONOMY / Corona;
- 7513 SOLAR PHYSICS;
- ASTROPHYSICS;
- AND ASTRONOMY / Coronal mass ejections;
- 7524 SOLAR PHYSICS;
- ASTROPHYSICS;
- AND ASTRONOMY / Magnetic fields