| 其他摘要 | Solar filaments (also known as prominences when observed at the solar limb) are relatively cold, dark materials suspended in the solar atmosphere and held together by a magnetic field, which exhibit a variety of motions, such as oscillations or waves and even eruptions. Information on the filament magnetic field is essential to understand the formation, stability, and eruption of a filament. This paper uses the study of large amplitude filament oscillations as an entry point to try to diagnose the magnetic field information of the filament in terms of the motion of a two-sided-loop jet in the magnetic structure of the filament and the simultaneous large amplitude longitudinal andtransverse filament oscillations triggered by a two-sided-loop jet. In Chapter 1, we provide a more in-depth introduction to solar filaments and their large amplitude oscillations, starting with an introduction to solar physics in a step-by-step fashion. In Chapter 2, we present the observational data sources and data analysis methods required for the study. The main findings are summarised as follows:Two-sided-loop jets illuminate the filament magnetic structureUsing stereoscopic observations taken by the Solar Dynamics Observatory (SDO) and Solar TErrestrial RElations Observatory (STEREO), we studied the generation mechanism of a two-sided-loop jet (TJ) and the ejection process of the jet plasma into the overlying filament-cavity system. We find that the generation of the two-sided-loop jet was due to the magnetic reconnection between an emerging flux loop and the overlying filament. The jet’s two arms ejected along the filament axis during the initial stage. Then, the north arm was bifurcated into two parts at about 50 Mm from the reconnection site. After the bifurcation, the two bifurcated parts were along the filament axis and thecavity which hosted the filament, respectively. By tracing the ejecting plasma flows of the TJ inside the filament, we not only measured that the magnetic twist stored in the filament was at least 5𝜋 but also found that the fine magnetic structure of the filament cavity flux rope system is in good agreement with the theoretical results of Magnetic flux rope models. 2. Stereoscopic observation of transverse and longitudinal filament oscillationsWe report the first observations of simultaneous large-amplitude longitudinal and transverse oscillations of a quiescent filament triggered by a two-sided-loop jet formed by the magnetic reconnection between the filament and an emerging loop in the filament channel, recorded by SDO and STEREO. The north arm of the jet firstly pushed the filament mass moving northwardly along the magnetic field lines consisting of the coronal cavity, then some elevated filament mass fell back and started to oscillate longitudinally at the bottom of the cavity (i.e., the magnetic dip). The northernmost part of the filament also showed transverse oscillation simultaneously. The amplitude and period of the longitudinal (transverse) oscillation are 12.96 (2.99) Mm and 1.18 (0.33) hours, respectively. By using the method of filament seismology, the radius of curvature of the magnetic dip is about 151 Mm, consistent with that obtained by the 3D reconstruction (166 Mm). Using different physical parameters of the observed longitudinal and transverse oscillations, the magnetic field strength of the filament is estimated to be about 23 and 21 Gauss, respectively. By calculating the energy of the moving filament mass, the minimum energy of the jet is estimated to be about 1.96 × 1028 erg. We conclude that the newly formed jet can not only trigger simultaneous longitudinal and transverse oscillations in a single filament, but also can be used as a seismology tool for diagnosing filament information, such as the magnetic structure, magnetic field strength, and magnetic twists. In conclusion, we provide an outlook on the future development of large amplitude filament oscillations in terms of theoretical, observational and simulations, using the progress already made as an example. In addition to this, a growing number of observational events show that two-sided-loop jets, especially those produced in filament channel, are an extremely common phenomenon in coronal small-scale eruptions. Two-sided-loop jets play an indispensable role in the diagnosis of magnetic structures such as filaments and seismology analysis. |
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