A Magnetohydrodynamic Model Focused on the Configuration of Magnetic Field Responsible for a Solar Penumbral Microjet

• Published in: Astrophysical journal. Letters Vol. 715; no. 1; pp. L40 - L43
• Main Author: Magara, T
• Format: Journal Article
• Language: English
• Published: United States IOP Publishing 20.05.2010
• Subjects: ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ATMOSPHERES; FLUID MECHANICS; HYDRODYNAMICS; MAGNETIC FIELDS; MAGNETIC FLUX; MAGNETIC RECONNECTION; MAGNETOHYDRODYNAMICS; MAIN SEQUENCE STARS; MATHEMATICS; MECHANICS; SIMULATION; SOLAR ACTIVITY; STARS; STARSPOTS; STELLAR ACTIVITY; STELLAR ATMOSPHERES; SUN; SUNSPOTS; THREE-DIMENSIONAL CALCULATIONS; TOPOLOGY
• ISSN: 2041-8205; 2041-8213
• DOI: 10.1088/2041-8205/715/1/L40

In order to understand the configuration of magnetic field producing a solar penumbral microjet that was recently discovered by Hinode, we performed a magnetohydrodynamic simulation reproducing a dynamic process of how that configuration is formed in a modeled solar penumbral region. A horizontal magnetic flux tube representing a penumbral filament is placed in a stratified atmosphere containing the background magnetic field that is directed in a relatively vertical direction. Between the flux tube and the background field there forms the intermediate region in which the magnetic field has a transitional configuration, and the simulation shows that in the intermediate region magnetic reconnection occurs to produce a clear jet-like structure as suggested by observations. The result that a continuous distribution of magnetic field in three-dimensional space gives birth to the intermediate region producing a jet presents a new view about the mechanism of a penumbral microjet, compared to a simplistic view that two field lines, one of which represents a penumbral filament and the other the background field, interact together to produce a jet. We also discuss the role of the intermediate region in protecting the structure of a penumbral filament subject to microjets.