Light walls around sunspots observed by the Interface Region Imaging Spectrograph
Abstract
Context. The Interface Region Imaging Spectrograph (IRIS) mission provides high-resolution observations of the chromosphere and transition region. Using these data, some authors have reported the new finding of light walls above sunspot light bridges.
Aims: We try to determine whether the light walls exist somewhere else in active regions in addition to the light bridges. We also examine how the material of these walls evolves.
Methods: Employing six months of (from 2014 December to 2015 June) high tempo-spatial data from the IRIS, we find many light walls either around sunspots or above light bridges.
Results: For the first time, we report one light wall near an umbral-penumbral boundary and another along a neutral line between two small sunspots. The former light wall has a multilayer structure and is associated with the emergence of positive magnetic flux in the ambient negative field. The latter light wall is associated with a filament activation, and the wall body consists of the filament material, which flowed to a remote plage region with a negative magnetic field after the light wall disappeared.
Conclusions: These new observations reveal that these light walls are multilayer and multithermal structures that occur along magnetic neutral lines in active regions.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- May 2016
- DOI:
- 10.1051/0004-6361/201628216
- arXiv:
- arXiv:1604.00485
- Bibcode:
- 2016A&A...589L...7H
- Keywords:
-
- sunspots;
- Sun: atmosphere;
- Sun: filaments;
- prominences;
- Sun: UV radiation;
- Astrophysics - Solar and Stellar Astrophysics
- E-Print:
- 4 pages, 4 figures, Accepted for publication in A&