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Title: The Helium Warm Breeze in IBEX Observations As a Result of Charge-exchange Collisions in the Outer Heliosheath

Abstract

We simulated the signal due to neutral He atoms, observed by the Interstellar Boundary Explorer ( IBEX ), assuming that charge-exchange collisions between neutral He atoms and He{sup +} ions operate everywhere between the heliopause and a distant source region in the local interstellar cloud, where the neutral and charged components are in thermal equilibrium. We simulated several test cases of the plasma flow within the outer heliosheath (OHS) and investigated the signal generation for plasma flows both in the absence and in the presence of the interstellar magnetic field (ISMF). We found that a signal in the portion of IBEX data identified as being due to the Warm Breeze (WB) does not arise when a homogeneous plasma flow in front of the heliopause is assumed, but it appears immediately when any reasonable disturbance in its flow due to the presence of the heliosphere is assumed. We obtained a good qualitative agreement between the data selected for comparison and the simulations for a model flow with the velocity vector of the unperturbed gas and the direction and intensity of magnetic field adopted from recent determinations. We conclude that direct-sampling observations of neutral He atoms at 1 au from the Sunmore » are a sensitive tool for investigating the flow of interstellar matter in the OHS, that the WB is indeed the secondary population of interstellar helium, which was hypothesized earlier, and that the WB signal is consistent with the heliosphere distorted from axial symmetry by the ISMF.« less

Authors:
; ; ;  [1]
  1. Space Research Centre PAS (CBK PAN) Bartycka 18A 00-716 Warsaw (Poland)
Publication Date:
OSTI Identifier:
22663290
Resource Type:
Journal Article
Journal Name:
Astrophysical Journal
Additional Journal Information:
Journal Volume: 845; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0004-637X
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ATOMS; AXIAL SYMMETRY; CHARGE EXCHANGE; CLOUDS; DISTURBANCES; FLOW MODELS; HELIOSPHERE; HELIUM; HELIUM IONS; HOMOGENEOUS PLASMA; INTERSTELLAR MAGNETIC FIELDS; SIMULATION; SUN; THERMAL EQUILIBRIUM; VELOCITY

Citation Formats

Bzowski, Maciej, Kubiak, Marzena A., Czechowski, Andrzej, and Grygorczuk, Jolanta, E-mail: bzowski@cbk.waw.pl. The Helium Warm Breeze in IBEX Observations As a Result of Charge-exchange Collisions in the Outer Heliosheath. United States: N. p., 2017. Web. doi:10.3847/1538-4357/AA7ED5.
Bzowski, Maciej, Kubiak, Marzena A., Czechowski, Andrzej, & Grygorczuk, Jolanta, E-mail: bzowski@cbk.waw.pl. The Helium Warm Breeze in IBEX Observations As a Result of Charge-exchange Collisions in the Outer Heliosheath. United States. doi:10.3847/1538-4357/AA7ED5.
Bzowski, Maciej, Kubiak, Marzena A., Czechowski, Andrzej, and Grygorczuk, Jolanta, E-mail: bzowski@cbk.waw.pl. Thu . "The Helium Warm Breeze in IBEX Observations As a Result of Charge-exchange Collisions in the Outer Heliosheath". United States. doi:10.3847/1538-4357/AA7ED5.
@article{osti_22663290,
title = {The Helium Warm Breeze in IBEX Observations As a Result of Charge-exchange Collisions in the Outer Heliosheath},
author = {Bzowski, Maciej and Kubiak, Marzena A. and Czechowski, Andrzej and Grygorczuk, Jolanta, E-mail: bzowski@cbk.waw.pl},
abstractNote = {We simulated the signal due to neutral He atoms, observed by the Interstellar Boundary Explorer ( IBEX ), assuming that charge-exchange collisions between neutral He atoms and He{sup +} ions operate everywhere between the heliopause and a distant source region in the local interstellar cloud, where the neutral and charged components are in thermal equilibrium. We simulated several test cases of the plasma flow within the outer heliosheath (OHS) and investigated the signal generation for plasma flows both in the absence and in the presence of the interstellar magnetic field (ISMF). We found that a signal in the portion of IBEX data identified as being due to the Warm Breeze (WB) does not arise when a homogeneous plasma flow in front of the heliopause is assumed, but it appears immediately when any reasonable disturbance in its flow due to the presence of the heliosphere is assumed. We obtained a good qualitative agreement between the data selected for comparison and the simulations for a model flow with the velocity vector of the unperturbed gas and the direction and intensity of magnetic field adopted from recent determinations. We conclude that direct-sampling observations of neutral He atoms at 1 au from the Sun are a sensitive tool for investigating the flow of interstellar matter in the OHS, that the WB is indeed the secondary population of interstellar helium, which was hypothesized earlier, and that the WB signal is consistent with the heliosphere distorted from axial symmetry by the ISMF.},
doi = {10.3847/1538-4357/AA7ED5},
journal = {Astrophysical Journal},
issn = {0004-637X},
number = 1,
volume = 845,
place = {United States},
year = {2017},
month = {8}
}