Voyager 1 Electron Densities in the Very Local Interstellar Medium to beyond 160 au

The two Voyager spacecraft have been exploring the interstellar medium beyond the heliopause since 2012 (Voyager 1) and 2018 (Voyager 2). Electron plasma oscillations and a quasi-thermal noise line at the electron plasma frequency have enabled the determination of the electron density in this region...

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Main Author: W. S. Kurth
Format: Article
Language:English
Published: IOP Publishing 2024-01-01
Series:The Astrophysical Journal Letters
Subjects:
Online Access:https://doi.org/10.3847/2041-8213/ad2617
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author W. S. Kurth
author_facet W. S. Kurth
author_sort W. S. Kurth
collection DOAJ
description The two Voyager spacecraft have been exploring the interstellar medium beyond the heliopause since 2012 (Voyager 1) and 2018 (Voyager 2). Electron plasma oscillations and a quasi-thermal noise line at the electron plasma frequency have enabled the determination of the electron density in this region, revealing a radial density gradient convolved with shocks and pressure fronts. Voyager 1 has a functioning wideband receiver that provides high-spectral-resolution observations allowing the detection of the quasi-thermal noise line and has now provided electron densities to 161.4 au. Since a pressure pulse observed in 2020 around day 146 at about 149 au, the density has remained relatively constant at 0.147 cm ^−3 based on the most recent observations from 2023, suggesting that Voyager 1 has reached a broad density peak and possibly a new regime.
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spelling doaj.art-6e2377ba84d54816a197534f0f298e622024-02-20T17:17:42ZengIOP PublishingThe Astrophysical Journal Letters2041-82052024-01-019631L610.3847/2041-8213/ad2617Voyager 1 Electron Densities in the Very Local Interstellar Medium to beyond 160 auW. S. Kurth0https://orcid.org/0000-0002-5471-6202Department of Physics and Astronomy, University of Iowa , Iowa City, IA 52242, USAThe two Voyager spacecraft have been exploring the interstellar medium beyond the heliopause since 2012 (Voyager 1) and 2018 (Voyager 2). Electron plasma oscillations and a quasi-thermal noise line at the electron plasma frequency have enabled the determination of the electron density in this region, revealing a radial density gradient convolved with shocks and pressure fronts. Voyager 1 has a functioning wideband receiver that provides high-spectral-resolution observations allowing the detection of the quasi-thermal noise line and has now provided electron densities to 161.4 au. Since a pressure pulse observed in 2020 around day 146 at about 149 au, the density has remained relatively constant at 0.147 cm ^−3 based on the most recent observations from 2023, suggesting that Voyager 1 has reached a broad density peak and possibly a new regime.https://doi.org/10.3847/2041-8213/ad2617Interstellar mediumInterstellar plasmaSpace plasmasAstrosphere interstellar medium interactions
spellingShingle W. S. Kurth
Voyager 1 Electron Densities in the Very Local Interstellar Medium to beyond 160 au
The Astrophysical Journal Letters
Interstellar medium
Interstellar plasma
Space plasmas
Astrosphere interstellar medium interactions
title Voyager 1 Electron Densities in the Very Local Interstellar Medium to beyond 160 au
title_full Voyager 1 Electron Densities in the Very Local Interstellar Medium to beyond 160 au
title_fullStr Voyager 1 Electron Densities in the Very Local Interstellar Medium to beyond 160 au
title_full_unstemmed Voyager 1 Electron Densities in the Very Local Interstellar Medium to beyond 160 au
title_short Voyager 1 Electron Densities in the Very Local Interstellar Medium to beyond 160 au
title_sort voyager 1 electron densities in the very local interstellar medium to beyond 160 au
topic Interstellar medium
Interstellar plasma
Space plasmas
Astrosphere interstellar medium interactions
url https://doi.org/10.3847/2041-8213/ad2617
work_keys_str_mv AT wskurth voyager1electrondensitiesintheverylocalinterstellarmediumtobeyond160au