Observational Evidence of Magnetic Reconnection for Brightenings and Transition Region Arcades in IRIS observations

Abstract

By using a new method of forced-field extrapolation, we study the emerging flux region AR 11850 observed by the Interface Region Imaging Spectrograph (IRIS) and Solar Dynamical Observatory (SDO). Our results suggest that the bright points (BPs) in this emerging region have responses in lines formed from the upper photosphere to the transition region, with a relatively similar morphology. They have an oscillation of several minutes according to the Atmospheric Imaging Assembly (AIA) data at 1600 and 1700 A . The ratio between the BP intensities measured in 1600 A and 1700 A filtergrams reveals that these BPs are heated differently. Our analysis of the Helioseismic and Magnetic Imager (HMI) vector magnetic field and the corresponding topology in AR11850 indicates that the BPs are located at the polarity inversion line (PIL) and most of them related with magnetic reconnection or cancelation. The heating of the BPs might be different due to different magnetic topology. We find that the heating due to the magnetic cancelation would be stronger than the case of bald patch reconnection. The plasma density rather than the magnetic field strength could play a dominant role in this process. Based on physical conditions in the lower atmosphere, our forced-field extrapolation shows consistent results between the bright arcades visible in slit-jaw image (SJI) 1400 A and the extrapolated field lines that pass through the bald patches. It provides a reliable observational evidence for testing the mechanism of magnetic reconnection for the BPs and arcades in emerging flux region, as proposed in simulation works.

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Cited by in corpus (8)

• Magnetic reconnection in strongly magnetized regions of the low solar chromosphere
• Flame-like Ellerman Bombs and Their Connection to Solar UV Bursts
• A Magnetic Reconnection model for Hot Explosions in the Cool Atmosphere of the Sun
• IRIS observations of magnetic interactions in the solar atmosphere between pre-existing and emerging magnetic fields. II. UV emission properties
• Multi thermal atmosphere of a mini solar flare during magnetic reconnection observed with IRIS
• Cancellation of Small-Scale Magnetic Features
• Transition region loops in the very late phase of flux-emergence in IRIS sit-and-stare observations
• Reminiscences