TY - JOUR
T1 - Oscillatory Reconnection of a 2D X-point in a hot coronal plasma
AU - Karampelas, Konstantinos
AU - McLaughlin, James
AU - Botha, Gert
AU - Regnier, Stephane
N1 - Funding information: All authors acknowledge UK Science and Technology Facilities Council (STFC) support from grant ST/T000384/1. K.K. also acknowledges support by an FWO (Fonds voor Wetenschappelijk Onderzoek – Vlaanderen) postdoctoral fellowship (1273221N). This work used the Oswald High Performance Computing facility operated by Northumbria University (UK).
PY - 2022/2/1
Y1 - 2022/2/1
N2 - Oscillatory reconnection (a relaxation mechanism with periodic changes in connectivity) has been proposed as a potential physical mechanism underpinning several periodic phenomena in the solar atmosphere, including, but not limited to, quasi-periodic pulsations (QPPs). Despite its importance, however, the mechanism has never been studied within a hot, coronal plasma. We investigate oscillatory reconnection in a one million Kelvin plasma by solving the fully-compressive, resistive MHD equations for a 2D magnetic X-point under coronal conditions using the PLUTO code. We report on the resulting oscillatory reconnection including its periodicity and decay rate. We observe a more complicated oscillating profile for the current density compared to that found for a cold plasma, due to mode-conversion at the equipartition layer. We also consider, for the first time, the effect of adding anisotropic thermal conduction to the oscillatory reconnection mechanism, and we find this simplifies the spectrum of the oscillation profile and increases the decay rate. Crucially, the addition of thermal conduction does not prevent the oscillatory reconnection mechanism from manifesting. Finally, we reveal a relationship between the equilibrium magnetic field strength, decay rate, and period of oscillatory reconnection, which opens the tantalising possibility of utilizing oscillatory reconnection as a seismological tool.
AB - Oscillatory reconnection (a relaxation mechanism with periodic changes in connectivity) has been proposed as a potential physical mechanism underpinning several periodic phenomena in the solar atmosphere, including, but not limited to, quasi-periodic pulsations (QPPs). Despite its importance, however, the mechanism has never been studied within a hot, coronal plasma. We investigate oscillatory reconnection in a one million Kelvin plasma by solving the fully-compressive, resistive MHD equations for a 2D magnetic X-point under coronal conditions using the PLUTO code. We report on the resulting oscillatory reconnection including its periodicity and decay rate. We observe a more complicated oscillating profile for the current density compared to that found for a cold plasma, due to mode-conversion at the equipartition layer. We also consider, for the first time, the effect of adding anisotropic thermal conduction to the oscillatory reconnection mechanism, and we find this simplifies the spectrum of the oscillation profile and increases the decay rate. Crucially, the addition of thermal conduction does not prevent the oscillatory reconnection mechanism from manifesting. Finally, we reveal a relationship between the equilibrium magnetic field strength, decay rate, and period of oscillatory reconnection, which opens the tantalising possibility of utilizing oscillatory reconnection as a seismological tool.
KW - Magnetohydrodynamics
KW - Solar magnetic reconnection
KW - Solar coronal seismology
KW - Solar coronal waves
KW - Magnetohydrodynamical simulations
UR - http://www.scopus.com/inward/record.url?scp=85125832453&partnerID=8YFLogxK
U2 - 10.3847/1538-4357/ac3b53
DO - 10.3847/1538-4357/ac3b53
M3 - Article
SN - 0004-637X
VL - 925
SP - 1
EP - 13
JO - Astrophysical Journal
JF - Astrophysical Journal
IS - 2
M1 - 195
ER -