간행물

천문학회지 KCI 등재 SCOPUS Journal of The Korean Astronomical Society

권호리스트/논문검색
이 간행물 논문 검색

권호

제54권 제5호 (2021년 10월) 2

1.
2021.10 구독 인증기관 무료, 개인회원 유료
We present an updated version of the multilayer spectral inversion (MLSI) recently proposed as a technique to infer the physical parameters of plasmas in the solar chromosphere from a strong absorption line. In the original MLSI, the absorption pro le was constant over each layer of the chromosphere, whereas the source function was allowed to vary with optical depth. In our updated MLSI, the absorption pro le is allowed to vary with optical depth in each layer and kept continuous at the interface of two adjacent layers. We also propose a new set of physical requirements for the parameters useful in the constrained model tting. We apply this updated MLSI to two sets of Hα and Ca ii line spectral data taken by the Fast Imaging Solar Spectrograph (FISS) from a quiet region and an active region, respectively. We nd that the new version of the MLSI satisfactorily ts most of the observed line pro les of various features, including a network feature, an internetwork feature, a mottle feature in a quiet region, and a plage feature, a superpenumbral bril, an umbral feature, and a fast down ow feature in an active region. The MLSI can also yield physically reasonable estimates of hydrogen temperature and nonthermal speed as well as Doppler velocities at different atmospheric levels. We conclude that the MLSI is a very useful tool to analyze the Hα line and the Ca ii 8542 line spectral daya, and will promote the investigation of physical processes occurring in the solar photosphere and chromosphere.
5,100원
2.
2021.10 구독 인증기관 무료, 개인회원 유료
We investigate ow and magnetic structure of a solar prominence with a focus on how the magnetic eld originally determined by subsurface dynamics gives rise to the structure. We perform a magnetohydrodynamic simulation that reproduces the self-consistent evolution of a ow and the magnetic eld passing freely through the solar surface. By analyzing Lagrangian displacements of magnetized plasma elements, we demonstrate the ow structure that is naturally incorporated to the magnetic structure of the prominence formed via dynamic interaction between the ow and the magnetic eld. Our results explain a diverging ow on a U-loop, a counterclockwise downdraft along a rotating eld line, acceleration and deceleration of a down ow along an S-loop, and partial emergence of a W-loop, which may play key roles in determining structural properties of the prominence.
4,600원