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Title: PLASMA FLOWS AT VOYAGER 2 AWAY FROM THE MEASURED SUPRATHERMAL PRESSURES

Plasma flows measured by Voyager 2 show a clear rotation away from radially outward with increasing penetration into the inner heliosheath while the overall flow speed remains roughly constant. However, the direction of rotation is far more into the transverse, and less into the polar direction, than predicted. No current model reproduces the key observational results of (1) the direction of flow rotation or (2) constancy of the flow speed. Here we show that the direction is consistent with flow away from the region of maximum pressure in the inner heliosheath, ∼20° south of the upwind direction, as measured by the Interstellar Boundary Explorer (IBEX). Further, we show that the dominance of the suprathermal ion pressure in the inner heliosheath measured by IBEX can explain both the observed flow rotation and constancy of the flow speed. These results indicate the critical importance of suprathermal ions in the physics of the inner heliosheath and have significant implications for understanding this key region of the heliosphere's interstellar interaction and astrophysical plasmas more broadly.
Authors:
 [1] ;  [2]
  1. Southwest Research Institute, San Antonio, TX 78228 (United States)
  2. University of New Hampshire, Durham, NH 03824 (United States)
Publication Date:
OSTI Identifier:
22364918
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal Letters; Journal Volume: 795; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ASTROPHYSICS; HELIOSPHERE; INTERSTELLAR SPACE; MAGNETIC FIELDS; PLASMA; ROTATION; SOLAR WIND; SUN; VELOCITY; VOYAGER SPACE PROBES