Three-dimensional Density Structure of a Solar Coronal Streamer Observed by SOHO/LASCO and STEREO/COR2 in Quadrature

Abstract

Helmet streamers are a prominent manifestation of magnetic structures with current sheets in the solar corona. These large-scale structures are regions with high plasma density, overlying active regions and filament channels. We investigate the three-dimensional (3D) structure of a coronal streamer, observed simultaneously by white-light coronagraphs from two vantage points near quadrature (SOHO/LASCO and STEREO/COR2). We design a forward model based on plausible assumptions about the 3D streamer structure taken from physical models (a plasma slab centered around a current sheet). The streamer stalk is approximated by a plasma slab, with electron density that is characterized by three separate functions describing the radial, transverse and face-on profiles respectively. For the first time, we simultaneously fit the observational data from SOHO and STEREO using a multivariate minimization algorithm. The streamer plasma sheet contains a number of brighter and darker ray-like structures with the density contrast up to about a factor 3 between them. The densities derived using polarized and unpolarized data are similar. We demonstrate that our model corresponds well to the observations.

arXiv comment16 pages, 16 figures, 2 tables. Accepted for publication in The Astrophysical Journal

References in corpus (8)

• Streamer Waves Driven by Coronal Mass Ejections
• Streamer Blowout Coronal Mass Ejections: Their Properties and Relation to the Coronal Magnetic Field Structure
• Dynamics of Coronal-Hole Boundaries
• An atlas of coronal electron density at 5Rs I: Data processing and calibration
• Streamer Wave Events Observed in Solar Cycle 23
• The Thomson Surface. II. Polarization
• An atlas of coronal electron density at 5Rs II: A spherical harmonic method for density reconstruction
• An Empirical 3D Model of the Large-scale Coronal Structure Based on the Distribution of Prominences on the Solar Disk

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