A Porous, Layered Heliopause

Abstract

The picture of the heliopause (HP) -- the boundary between the domains of the sun and the local interstellar medium (LISM) -- as a pristine interface with a large rotation in the magnetic field fails to describe recent Voyager 1 (V1) spacecraft data. Magnetohydrodynamic (MHD) simulations of the global heliosphere reveal that the rotation angle of the magnetic field across the HP at V1 is small. Particle-in-cell simulations, based on cuts through the MHD model at the location of V1, suggest that the sectored region of the heliosheath (HS) produces large-scale magnetic islands that reconnect with the interstellar magnetic field and mix LISM and HS plasma. Cuts across the simulation data reveal multiple, anti-correlated jumps in the number densities of LISM and HS particles at the magnetic separatrices of the islands, similar to those observed by V1. A model is presented, based on both the observations and simulation data, of the HP as a porous, multi-layered structure threaded by magnetic fields. This model further suggests that, contrary to the conclusions of recent papers, V1 has already crossed the HP.

7 pages, 4 figures

Cited by in corpus (16)

• On the Rotation of the Magnetic Field Across the Heliopause
• The Twist of the Draped Interstellar Magnetic Field Ahead of the Heliopause: A Magnetic Reconnection Driven Rotational Discontinuity
• Draping of the Interstellar Magnetic Field over the Heliopause - A Passive Field Model
• Electron thermal conduction as a possible mechanism to make the inner heliosheath thnner
• Is Voyager 1 Inside an Interstellar Flux Transfer Event?
• Multiple current sheet systems in the outer heliosphere: Energy release and turbulence
• Advective transport of interstellar plasma into the heliosphere across the reconnecting heliopause
• The three-dimensional evolution of ion-scale current sheets: tearing and drift-kink instabilities in the presence of proton temperature anisotropy
• The formation of magnetic depletions and flux annihilation due to reconnection in the heliosheath
• Galactic Cosmic Rays measured by UVS on Voyager 1 and the end of the modulation: Is the upwind heliopause a collapsed charge-exchange layer?
• The strong effect of electron thermal conduction on the global structure of the heliosphere
• Transient Heliosheath Modulation
• MHD flows at astropauses and in astrotails
• Voyager observations in the distant heliosheath: An analogy with ISEE-3 observations in the deep geomagnetic tail
• Magnetized jets driven by the sun: the structure of the heliosphere revisited
• Variations in the pickup ion density structure in response to the growth of the Kelvin--Helmholtz instability along the heliopause