skip to main content

SciTech ConnectSciTech Connect

Title: Dependence of energetic ion and electron intensities on proximity to the magnetically sectored heliosheath: Voyager 1 and 2 observations

Taken together, the Voyager 1 and 2 (V1 and V2) spacecraft have collected over 11 yr of data in the heliosheath. Despite extensive study, energetic particles and magnetic fields measured in the heliosheath have not been reconciled by existing models. In particular, the differences between the energetic particle intensity variations at V1 and V2 are unexplained. While energetic particle intensities at V1 change gradually over 7 yr in the heliosheath, those at V2 vary by a factor ∼10 in 1 yr. Energetic particle intensities at V2 show temporally coherent variations over a broad range of species and energies: from suprathermal ions (10s of keV) to galactic cosmic rays (>1 GeV), as well as electrons from 10s of keV to >100 MeV, corresponding to a range ∼10{sup 4} in particle gyroradii. Here we suggest that many of the intensity variations of energetic particle populations in the heliosheath are organized by their proximity to two fundamentally different regions—the unipolar heliosheath (UHS) and the sectored heliosheath (SHS). The SHS is a region of enhanced particle intensities, wherein particle transport, acceleration, and magnetic connectivity differ from those in the UHS. The SHS may serve as either a reservoir of energetic particles or as amore » region of enhanced transport, depending on the particle species and energy. Comparatively, particle intensities in the UHS are greatly reduced. We propose that the boundary between the SHS and UHS plays as important a role in the physics of heliosheath particles and fields as do the termination shock and heliopause.« less
Authors:
; ; ;  [1] ; ;  [2] ;  [3]
  1. Applied Physics Laboratory, Johns Hopkins University, Laurel, MD 20723 (United States)
  2. Department of Physics, University of Maryland, College Park, MD 20742 (United States)
  3. Astronomy Department, Boston University, 725 Commonwealth Avenue, Boston, MA 02215 (United States)
Publication Date:
OSTI Identifier:
22348120
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 781; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ACCELERATION; COSMIC RADIATION; DIFFUSION; ELECTRONS; GEV RANGE; HELIOSPHERE; KEV RANGE; MAGNETIC FIELDS; MAGNETIC RECONNECTION; MEV RANGE; SOLAR WIND; SUN; TAIL IONS; VOYAGER SPACE PROBES