Comparing magnetic field extrapolations with measurements of magnetic loops
Abstract
We compare magnetic field extrapolations from a photospheric magnetogram with the observationally inferred structure of magnetic loops in a newly developed active region. This is the first time that the reconstructed 3D-topology of the magnetic field is available to test the extrapolations. We compare the observations with potential fields, linear force-free fields and non-linear force-free fields. This comparison reveals that a potential field extrapolation is not suitable for a reconstruction of the magnetic field in this young, developing active region. The inclusion of field-line-parallel electric currents, the so called force-free approach, gives much better results. Furthermore, a non-linear force-free computation reproduces the observations better than the linear force-free approximation, although no free parameters are available in the former case.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- April 2005
- DOI:
- 10.1051/0004-6361:20042421
- arXiv:
- arXiv:0801.4519
- Bibcode:
- 2005A&A...433..701W
- Keywords:
-
- Sun: magnetic fields;
- Sun: corona;
- Sun: chromosphere;
- Astrophysics
- E-Print:
- 5 pages, 3 figures