| Item type |
itemtype_ver1(1) |
| 公開日 |
2022-01-20 |
| タイトル |
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タイトル |
Coronal Density Measurements Using Giant Radio Pulses of the Crab Pulsar at the Cycle 24/25 Minimum |
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言語 |
en |
| 著者 |
Tokumaru, Munetoshi
Maeda, Ryuya
Tawara, Kaito
Takefuji, Kazuhiro
Terasawa, Toshio
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| アクセス権 |
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|
アクセス権 |
open access |
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アクセス権URI |
http://purl.org/coar/access_right/c_abf2 |
| 権利 |
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|
言語 |
en |
|
権利情報 |
This article is licensed under a Creative Commons Attribution 4.0 International License |
| 内容記述 |
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|
内容記述タイプ |
Abstract |
|
内容記述 |
Accurate measurements of the coronal plasma density profile, which varies with the solar cycle (SC), are necessary to elucidate the solar wind acceleration. In this study, the Crab pulsar is observed using the 327 MHz radio telescope at the Toyokawa Observatory of the Institute for Space-Earth Environmental Research of Nagoya University to investigate the coronal plasma density profile for radial distances between 5 and 60 solar radii at the SC24/25 minimum. We derive the dispersion measures (DMs) that represent the integration of plasma density along the line of sight (LOS) for giant radio pulses of the Crab pulsar. We find that the observed DMs increased above the interstellar background level when the LOS for the Crab pulsar approached the Sun in mid-June 2018 and 2019. This increase in DM is attributed to the effect of the coronal plasma. We determine the plasma density distribution by fitting a spherically symmetric model to the observed DM data. The flat radial slopes of the best-fit model are consistent with pulsar observations in the low-activity periods of past SCs, and they are attributed to the effect of the coronal hole over the south pole of the Sun. Our results show that the density level near the Sun is similar to those observed in the low activity periods of past SCs, implying recovery of the coronal plasma density from a significant reduction at the SC23/24 minimum. |
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言語 |
en |
| 出版者 |
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出版者 |
Springer |
|
言語 |
en |
| 言語 |
|
|
言語 |
eng |
| 資源タイプ |
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|
資源タイプ識別子 |
http://purl.org/coar/resource_type/c_6501 |
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資源タイプ |
journal article |
| 出版タイプ |
|
|
出版タイプ |
AM |
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出版タイプResource |
http://purl.org/coar/version/c_ab4af688f83e57aa |
| 関連情報 |
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|
関連タイプ |
isVersionOf |
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|
識別子タイプ |
DOI |
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関連識別子 |
https://doi.org/10.1007/s11207-021-01939-6 |
| 収録物識別子 |
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収録物識別子タイプ |
PISSN |
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収録物識別子 |
0038-0938 |
| 書誌情報 |
en : Solar Physics
巻 297,
号 1,
p. 10,
発行日 2022-01-17
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| ファイル公開日 |
|
|
日付 |
2022-01-20 |
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日付タイプ |
Available |
Tokumaru2022_Article_CoronalDensityMeasurementsUsin.pdf (2 MB)
