Magnetic reconnection in the heliosheath and its signatures and consequences
Abstract
The sectored magnetic field due to the flapping of the heliospheric current sheet compresses across the termination shock and may reconnect in the heliosheath, driving the anomalous cosmic rays and producing a sea of elongated magnetic bubbles. A number of Voyager observations are consistent with the bubble picture of the heliosheath, including flow enhancements, magnetic field compressions and strongly-altered transport properties. We are exploring large-scale structure of the the 3-D heliosheath with MHD simulations and the dynamics of magnetic reconnection and resultant magnetic bubbles with PIC simulations. The goal is to understand particle acceleration and how the resulting complex magnetic field will impact the transport of energetic particles, including galactic cosmic rays. We find that magnetic bubbles form as fully 3-D rather than 2-D objects. Because of the high beta conditions of the helioosheath, the characteristic signatures of magnetic reconnection differ greatly from that typical of 1AU. Reconnection is largely quenched once bubbles reach characteristic widths of the order of the sector spacing and the bubble cores bump against the marginal firehose condition. The characteristic signatures of bubbles are being identified for comparison with the magnetic field data from Voyager.
- Publication:
-
39th COSPAR Scientific Assembly
- Pub Date:
- July 2012
- Bibcode:
- 2012cosp...39..479D