Chromospheric recurrent jets in a sunspot group and their intergranular origin

Zhao, J., Su, J., Yang, X., Li, H., Schmieder, B., Ahn, K. and Cao, W. (2022) Chromospheric recurrent jets in a sunspot group and their intergranular origin. Astrophysical Journal, 932(2), 95. (doi: 10.3847/1538-4357/ac6e3b)

Abstract

We report on high-resolution observations of recurrent fan-like jets by the Goode Solar Telescope in multiple wavelengths inside a sunspot group. The dynamics behavior of the jets is derived from the Hα line profiles. Quantitative values for one well-identified event have been obtained, showing a maximum projected velocity of 42 km s−1 and a Doppler shift of the order of 20 km s−1. The footpoints/roots of the jets have a lifted center on the Hα line profile compared to the quiet Sun, suggesting a long-lasting heating at these locations. The magnetic field between the small sunspots in the group shows a very high resolution pattern with parasitic polarities along the intergranular lanes accompanied by high-velocity converging flows (4 km s−1) in the photosphere. Magnetic cancellations between the opposite polarities are observed in the vicinity of the footpoints of the jets. Along the intergranular lanes horizontal magnetic field around 1000 G is generated impulsively. Overall, all the kinetic features at the different layers through the photosphere and chromosphere favor a convection-driven reconnection scenario for the recurrent fan-like jets and evidence a site of reconnection between the photosphere and chromosphere corresponding to the intergranular lanes.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Schmieder, Prof Brigitte
• Authors: Zhao, J., Su, J., Yang, X., Li, H., Schmieder, B., Ahn, K., and Cao, W.
• College/School: College of Science and Engineering > School of Physics and Astronomy
• Journal Name: Astrophysical Journal
• Publisher: IOP Publishing
• ISSN: 0004-637X
• ISSN (Online): 1538-4357
• Copyright Holders: Copyright © The Author(s) 2022
• First Published: First published in Astrophysical Journal 932(2): 95
• Publisher Policy: Reproduced under a Creative Commons licence