Near the Boundary of the Heliosphere: A Flow Transition Region

Since April of 2010, Voyager 1 has been immersed in a region of near zero radial flows, where the solar wind seems to have stopped. The existence of this region contradicts current models that predict that the radial flows will go to zero only at the heliopause. These models, however, do not include the sector region (or include it in a kinematic fashion), where the solar magnetic field periodically reverses polarity. Here we show that the presence of the sector region in the heliosheath, where reconnection occurs, fundamentally alters the flows, giving rise to a Flow Transition Region (FTR), where the flow abruptly turns and the radial velocity becomes near zero or negative. We estimate, based on a simulation, that at the Voyager 1 location, the thickness of the FTR is around 7–11 AU.