Do anomalous cosmic rays modify the termination shock?

V. Florinski, G. P. Zank, J. Randy Jokipii, E. C. Stone, A. C. Cummings

Research output: Contribution to journalArticle

43 Citations (Scopus)

Abstract

This work extends our previous two-dimensional self-consistent model of the cosmic rays interacting with the solar wind to include anomalous cosmic rays. As before, energetic particles are described kinetically using a Parker equation. The model includes diffusion, convection, and drift effects, as well as shock and compression acceleration and expansion cooling by nonuniform solar wind flow. A new numerical model has been developed featuring an adaptive-mesh refinement algorithm to accommodate small diffusive length scales of low-energy shock-accelerated particles. We show that anomalous cosmic rays have only a minor effect on the termination shock during the time near solar minima. Specifically, cosmic-ray gradients cause the subshock to move away from the Sun by about 1 AU with its compression ratio decreasing by about 5% compared to the reference case without cosmic-ray effects. We also study the effect of solar wind slowdown by charge exchange downstream of the termination shock, producing compressive flow in this region and resulting in additional acceleration of anomalous cosmic rays in the heliosheath. For the first time, spectra calculated with our self-consistent model show a good agreement with the cosmic-ray data from the two Voyager spacecraft, giving more confidence in the model predictions than the previous parametric studies.

Original languageEnglish (US)
Pages (from-to)1169-1181
Number of pages13
JournalAstrophysical Journal
Volume610
Issue number2 I
DOIs
StatePublished - Aug 1 2004

Fingerprint

cosmic ray
cosmic rays
shock
solar wind
compression
compression ratio
energetic particles
charge exchange
confidence
spacecraft
sun
convection
energetics
cooling
gradients
expansion
effect
causes
prediction
predictions

Keywords

  • Acceleration of particles
  • Cosmic rays
  • Interplanetary medium
  • Shock waves
  • Solar wind

ASJC Scopus subject areas

  • Space and Planetary Science

Cite this

Florinski, V., Zank, G. P., Jokipii, J. R., Stone, E. C., & Cummings, A. C. (2004). Do anomalous cosmic rays modify the termination shock? Astrophysical Journal, 610(2 I), 1169-1181. https://doi.org/10.1086/421901

Do anomalous cosmic rays modify the termination shock? / Florinski, V.; Zank, G. P.; Jokipii, J. Randy; Stone, E. C.; Cummings, A. C.

In: Astrophysical Journal, Vol. 610, No. 2 I, 01.08.2004, p. 1169-1181.

Research output: Contribution to journalArticle

Florinski, V, Zank, GP, Jokipii, JR, Stone, EC & Cummings, AC 2004, 'Do anomalous cosmic rays modify the termination shock?', Astrophysical Journal, vol. 610, no. 2 I, pp. 1169-1181. https://doi.org/10.1086/421901
Florinski V, Zank GP, Jokipii JR, Stone EC, Cummings AC. Do anomalous cosmic rays modify the termination shock? Astrophysical Journal. 2004 Aug 1;610(2 I):1169-1181. https://doi.org/10.1086/421901
Florinski, V. ; Zank, G. P. ; Jokipii, J. Randy ; Stone, E. C. ; Cummings, A. C. / Do anomalous cosmic rays modify the termination shock?. In: Astrophysical Journal. 2004 ; Vol. 610, No. 2 I. pp. 1169-1181.
@article{298a414e78b04c34b23f951209a9a0e4,
title = "Do anomalous cosmic rays modify the termination shock?",
abstract = "This work extends our previous two-dimensional self-consistent model of the cosmic rays interacting with the solar wind to include anomalous cosmic rays. As before, energetic particles are described kinetically using a Parker equation. The model includes diffusion, convection, and drift effects, as well as shock and compression acceleration and expansion cooling by nonuniform solar wind flow. A new numerical model has been developed featuring an adaptive-mesh refinement algorithm to accommodate small diffusive length scales of low-energy shock-accelerated particles. We show that anomalous cosmic rays have only a minor effect on the termination shock during the time near solar minima. Specifically, cosmic-ray gradients cause the subshock to move away from the Sun by about 1 AU with its compression ratio decreasing by about 5{\%} compared to the reference case without cosmic-ray effects. We also study the effect of solar wind slowdown by charge exchange downstream of the termination shock, producing compressive flow in this region and resulting in additional acceleration of anomalous cosmic rays in the heliosheath. For the first time, spectra calculated with our self-consistent model show a good agreement with the cosmic-ray data from the two Voyager spacecraft, giving more confidence in the model predictions than the previous parametric studies.",
keywords = "Acceleration of particles, Cosmic rays, Interplanetary medium, Shock waves, Solar wind",
author = "V. Florinski and Zank, {G. P.} and Jokipii, {J. Randy} and Stone, {E. C.} and Cummings, {A. C.}",
year = "2004",
month = "8",
day = "1",
doi = "10.1086/421901",
language = "English (US)",
volume = "610",
pages = "1169--1181",
journal = "Astrophysical Journal",
issn = "0004-637X",
publisher = "IOP Publishing Ltd.",
number = "2 I",

}

TY - JOUR

T1 - Do anomalous cosmic rays modify the termination shock?

AU - Florinski, V.

AU - Zank, G. P.

AU - Jokipii, J. Randy

AU - Stone, E. C.

AU - Cummings, A. C.

PY - 2004/8/1

Y1 - 2004/8/1

N2 - This work extends our previous two-dimensional self-consistent model of the cosmic rays interacting with the solar wind to include anomalous cosmic rays. As before, energetic particles are described kinetically using a Parker equation. The model includes diffusion, convection, and drift effects, as well as shock and compression acceleration and expansion cooling by nonuniform solar wind flow. A new numerical model has been developed featuring an adaptive-mesh refinement algorithm to accommodate small diffusive length scales of low-energy shock-accelerated particles. We show that anomalous cosmic rays have only a minor effect on the termination shock during the time near solar minima. Specifically, cosmic-ray gradients cause the subshock to move away from the Sun by about 1 AU with its compression ratio decreasing by about 5% compared to the reference case without cosmic-ray effects. We also study the effect of solar wind slowdown by charge exchange downstream of the termination shock, producing compressive flow in this region and resulting in additional acceleration of anomalous cosmic rays in the heliosheath. For the first time, spectra calculated with our self-consistent model show a good agreement with the cosmic-ray data from the two Voyager spacecraft, giving more confidence in the model predictions than the previous parametric studies.

AB - This work extends our previous two-dimensional self-consistent model of the cosmic rays interacting with the solar wind to include anomalous cosmic rays. As before, energetic particles are described kinetically using a Parker equation. The model includes diffusion, convection, and drift effects, as well as shock and compression acceleration and expansion cooling by nonuniform solar wind flow. A new numerical model has been developed featuring an adaptive-mesh refinement algorithm to accommodate small diffusive length scales of low-energy shock-accelerated particles. We show that anomalous cosmic rays have only a minor effect on the termination shock during the time near solar minima. Specifically, cosmic-ray gradients cause the subshock to move away from the Sun by about 1 AU with its compression ratio decreasing by about 5% compared to the reference case without cosmic-ray effects. We also study the effect of solar wind slowdown by charge exchange downstream of the termination shock, producing compressive flow in this region and resulting in additional acceleration of anomalous cosmic rays in the heliosheath. For the first time, spectra calculated with our self-consistent model show a good agreement with the cosmic-ray data from the two Voyager spacecraft, giving more confidence in the model predictions than the previous parametric studies.

KW - Acceleration of particles

KW - Cosmic rays

KW - Interplanetary medium

KW - Shock waves

KW - Solar wind

UR - http://www.scopus.com/inward/record.url?scp=4043085630&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=4043085630&partnerID=8YFLogxK

U2 - 10.1086/421901

DO - 10.1086/421901

M3 - Article

AN - SCOPUS:4043085630

VL - 610

SP - 1169

EP - 1181

JO - Astrophysical Journal

JF - Astrophysical Journal

SN - 0004-637X

IS - 2 I

ER -