2008/04/08 by Toshifumi Shimizu, T. Shimizu, B. W. Lites +11 · 1 citation
Physics and Astronomy · #Astro and Planetary Science #Astronomy #Astrophysics #Chromosphere #Magnetic field #Magnetic flux #Mechanics #Photosphere #Physics #Solar and Space Plasma Dynamics #Solar flare #Solar observatory #Solar telescope #Stellar, planetary, and galactic studies #Sunspot #Supersonic speed #Telescope #astro-ph
paper · pdf · doi:10.1086/588775
26 pages, 10 figures, accepted for publication on the Astrophysical Journal
arxiv created 2008/04/08 · openalex publication_date 2008/06/13 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We report on new spectropolarimetric measurements with simultaneous filter imaging observation, revealing the frequent appearance of polarization signals indicating high-speed, probably supersonic, downflows that are associated with at least three different configurations of magnetic fields in the solar photosphere. The observations were carried out with the Solar Optical Telescope on board the Hinode satellite. High-speed downflows are excited when a moving magnetic feature is newly formed near the penumbral boundary of sunspots. Also, a new type of downflows is identified at the edge of sunspot umbra that lack accompanying penumbral structures. These may be triggered by the interaction of magnetic fields swept by convection with well-concentrated magnetic flux. Another class of high-speed downflows are observed in quiet Sun and sunspot moat regions. These are closely related to the formation of small concentrated magnetic flux patches. High-speed downflows of all types are transient time-dependent mass motions. These findings suggest that the excitation of supersonic mass flows are one of the key observational features of the dynamical evolution occurring in magnetic-field fine structures on the solar surface.