On the Observations of Rapid Forced Reconnection in the Solar Corona

• Published in: The Astrophysical journal Vol. 887; no. 2; pp. 137 - 148
• Main Authors: Srivastava, A. K., Mishra, S. K., Jelínek, P., Samanta, Tanmoy, Tian, Hui, Pant, Vaibhav, Kayshap, P., Banerjee, Dipankar, Doyle, J. G., Dwivedi, B. N.
• Format: Journal Article
• Language: English
• Published: Philadelphia The American Astronomical Society 20.12.2019; IOP Publishing
• Subjects: Astrophysics; Corona; Current sheets; Diffusion; Inflow; Magnetic reconnection; magnetohydrodynamics (MHD); Mathematical models; Numerical models; Plasma dynamics; Prominences; Solar activity; Solar corona; Solar observatories; Sun: corona; Sun: filaments, prominences; Sun: magnetic fields
• ISSN: 0004-637X; 1538-4357
• DOI: 10.3847/1538-4357/ab4a0c

Using multiwavelength imaging observations from the Atmospheric Imaging Assembly on board the Solar Dynamics Observatory on 2012 May 3, we present a novel physical scenario for the formation of a temporary X-point in the solar corona, where plasma dynamics are forced externally by a moving prominence. Natural diffusion was not predominant; however, a prominence driven inflow occurred first, forming a thin current sheet, thereafter enabling a forced magnetic reconnection at a considerably high rate. Observations in relation to the numerical model reveal that forced reconnection may rapidly and efficiently occur at higher rates in the solar corona. This physical process may also heat the corona locally even without establishing a significant and self-consistent diffusion region. Using a parametric numerical study, we demonstrate that the implementation of the external driver increases the rate of the reconnection even when the resistivity required for creating normal diffusion region decreases at the X-point. We conjecture that the appropriate external forcing can bring the oppositely directed field lines into the temporarily created diffusion region first via the plasma inflows as seen in the observations. The reconnection and related plasma outflows may occur thereafter at considerably larger rates.