Magnetic Field of Solar Dark Filaments Obtained from He I 10830 Angstrom Spectro-polarimetric Observation

Abstract

Solar filaments are dense and cool plasma clouds in the solar corona. They are supposed to be supported in a dip of coronal magnetic field. However, the models are still under argument between two types of the field configuration; one is the normal polarity model proposed by Kippenhahn & Schlueter (1957), and the other is the reverse polarity model proposed by Kuperus & Raadu (1974). To understand the mechanism that the filaments become unstable before the eruption, it is critical to know the magnetic structure of solar filaments. In this study, we performed the spectro-polarimetric observation in the He I (10830 angstrom) line to investigate the magnetic field configuration of dark filaments. The observation was carried out with the Domeless Solar Telescope at Hida Observatory with a polarization sensitivity of 3.0x10^-4. We obtained 8 samples of filaments in quiet region. As a result of the analysis of full Stokes profiles of filaments, we found that the field strengths were estimated as 8 - 35 Gauss. By comparing the direction of the magnetic field in filaments and the global distribution of the photospheric magnetic field, we determined the magnetic field configuration of the filaments, and we concluded that 1 out of 8 samples have normal polarity configuration, and 7 out of 8 have reverse polarity configuration.

27 pages, 17 figures. Accepted for the Publications of the Astronomical Society of Japan

References in corpus (12)

• Advanced Forward Modeling and Inversion of Stokes Profiles Resulting from the Joint Action of the Hanle and Zeeman Effects
• Magnetohydrodynamic Simulation of the X2.2 Solar Flare on 2011 February 15: II. Dynamics Connecting the Solar Flare and the Coronal Mass Ejection
• The magnetic field configuration of a solar prominence inferred from spectropolarimetric observations in the He I 10830 A triplet
• Multicomponent He I 10830 Å profiles in an active filament
• Spectro-polarimetric Imaging Reveals Helical Magnetic Fields in Solar Prominence Feet
• Spectropolarimetric analysis of an active region filament. I. Magnetic and dynamical properties from single component inversions
• A Data-constrained Magnetohydrodynamic Simulation of the X1.0 Solar Flare of 2021 October 28
• Spectropolarimetric analysis of an active region filament. II. Evidence of the limitations of a single component model
• Non-potential field formation in the X-shaped quadrupole magnetic field configuration
• Evolution of the Non-potential Magnetic Field in the Solar Active Region 12673 Based on a Nonlinear Force-free Modeling
• Extrapolation of Three-dimensional Magnetic Field Structure in Flare-productive Active Regions with Different Initial Conditions
• Observations of Photospheric Magnetic Structure below a Dark Filament using the Hinode Spectro-Polarimeter