Chromospheric Recurrent Jets in a Sunspot Group and Their Intergranular Origin

Jie Zhao , Jiangtao Su , Xu Yang , Hui Li , Brigitte Schmieder (1) , Kwangsu Ahn , Wenda Cao

1 LESIA - Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics

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.

Mots clés: Solar photosphere; Solar magnetic fields; Solar chromosphere; 1518; 1503; 1479; Astrophysics - Solar and Stellar Astrophysics

Domaines: Planète et Univers [physics]; Astrophysique [astro-ph]

Jie Zhao, Jiangtao Su, Xu Yang, Hui Li, Brigitte Schmieder, et al.. Chromospheric Recurrent Jets in a Sunspot Group and Their Intergranular Origin. The Astrophysical Journal, 2022, 932, ⟨10.3847/1538-4357/ac6e3b⟩. ⟨insu-03713300⟩