PSP Observations of a Slow Shock Pair Bounding a Large-Scale Plasmoid/Macro Magnetic Hole

Slow shocks are introduced to be the main dissipation sites in Petschek reconnection model, but they are seldom observed in interplanetary space. We report a slow shock pair bounding a plasmoid/macro magnetic hole observed by Parker Solar Probe. The jump conditions across the shocks are examined and confirmed to satisfy the Rankine-Hugoniot relations. The flow speed in the preshock and postshock regions of both shocks match up with the characteristics of slow shocks. The slow shock pair is suggested to be a part of a curved slow shock bounding the plasmoid produced by magnetic reconnection. Our findings append a new dissipation site to the picture of energy conversion through solar wind magnetic reconnection. In addition, the results suggest that plasmoids emitted by local magnetic reconnections could be a possible origin of macro magnetic holes in the solar wind.