An empirical 3D model of the large-scale coronal structure based on the distribution of H? filaments on the solar disk

Morgan, H.; Habbal, S. R., An empirical 3D model of the large-scale coronal structure based on the distribution of H? filaments on the solar disk, Astronomy and Astrophysics, Volume 464, Issue 1, March II 2007, pp.357-365

Despite the wealth of solar data currently available, the explicit connection between coronal streamers and features on the solar disk remains unresolved. Aims: To reproduce the large-scale coronal structure starting from the solar surface, an empirical three-dimensional (3D) model is used to test the assumption that such structure, namely streamers, is a consequence of twisted high-density sheets originating from prominences (or, equivalently, filaments) at the base of the corona. Methods: A 3D model is created whereby high-density sheets are placed above filaments on the solar disk, which twist and merge with height into a final radial configuration constrained by the oberved position of streamers stalks higher up in the corona. The observational constraints are provided by white light observations from the LASCO/C2 data during the declining phase of solar activity, spanning the end of Carrington Rotation (CR) 2005 and the start of CR 2006, i.e. July-August 2003, and the position of filaments from the corresponding H? synoptic maps of the Paris-Meudon Observatory. Results: The 3D model thus derived yields a reasonable agreement with the observed large-scale coronal structure, in particular the shape of large helmet streamers. Conclusions: .These results give confidence in the underlying assumption that large helmet streamers can be the result of the convergence of two or more sheet-like structures originating from a distribution of filaments on the solar disk. The model supports the view that streamers, during that time of the solar cycle, are often associated with multiple current sheets.

Peer reviewed