skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: A ROLE OF MAGNETOSONIC PULSES ON VARIATIONS OF VOYAGER-1 MeV ELECTRON INTENSITY IN THE HELIOSHEATH

Journal Article · · Astrophysical Journal Letters
; ; ;  [1];  [2];  [3];  [4]
  1. CSPAR, University of Alabama, Huntsville, AL 35899 (United States)
  2. Department of Astronomy, New Mexico State University, Las Cruces, NM 88003 (United States)
  3. NASA-MSFC, Huntsville, AL 35899 (United States)
  4. National Institute of Information and Communications Technology, Koganei, Tokyo 184-8795 (Japan)

Voyager 1 (V1) spacecraft observed electrons of 6-14 MeV in the heliosheath which showed several enhancements of significant flux variation. We compare these temporal electron flux variations, from the time when V1 crossed the termination shock (TS) up to mid-2008, with dynamical phenomena in the heliosheath that are obtained from our MHD simulations which are based on Voyager 2 (V2) observed solar-wind data. Our simulations indicate that all electron flux enhancements, except for one, correspond fairly well to the times when a magnetosonic (MS) pulse was driven downstream of the TS due to collision of interplanetary shock (IPS) or shock-driven MS pulse and its reflection in the heliosheath that either passed V1, or collided with the TS or with the plasma sheet near the heliopause (HP). This result suggests that these enhancements in the electron flux should correspond to either direct or indirect effects of MS pulses in the heliosheath driven by IPSs. The scale of the heliosphere is estimated by comparing V1-observed magnetic field intensity with the simulated intensity which suggests that V1 is possibly located near the HP within 4-8 AU at the present time.

OSTI ID:
22078541
Journal Information:
Astrophysical Journal Letters, Vol. 757, Issue 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 2041-8205
Country of Publication:
United States
Language:
English