Simulations of the Radiative Collapse of Plasmoids in Extreme Astrophysical Environments

In extreme HED astrophysical environments such as black hole coronae, jets and pulsar magnetospheres, radiation is an important signature of reconnection that modifies the energy partition, leading to cooling instabilities such as radiative collapse. Initial theoretical work done by Uzdensky and McKinney [Uzdensky & McKinney, 2011] describes radiative reconnection using a modified, compressible Sweet-Parker model, but this model does not include the effects of the plasmoid instability, which serves as a trigger for fast reconnection and forms magnetic islands or “plasmoids” [Loureiro et. al., 2007]. Simulations of the reconnection layer generated by a dual exploding aluminium wire array, using the Eulerian 3D resistive MHD code GORGON [Ciardi et. al., 2007], showed the formation and collapse of plasmoids in the presence of radiative cooling. Additionally, it was found that larger plasmoids collapse before smaller plasmoids. The presented work aims to elucidate the underlying mechanism of plasmoid collapse using AthenaPK, an astrophysical MHD code, whilst considering all terms involved in the balance of power density, including radiative loss, thermal conduction and ohmic heating, in a more fundamental geometry.