繰り返し発生する高速電波の周波数依存的偏振 - 発生源に関する含意
Yi Feng1,2,3, Di Li1,2,4, Yuan-Pei Yang5
1National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100101, China.
Science (New York, N.Y.)
|March 17, 2022
まとめ
高速電波の偏振は低い周波数で減少し,多経路分散を示している. これは超新星残骸のような 複合的な環境が FRBの繰り返しに近いことを示しています
科学分野:
- 天文学と天体物理学
- ラジオ天文学
- 宇宙 の 臨時 現象
背景:
- FRBは 銀河系外で発する 短い電波です
- FRBの二極化は 周囲の環境についての洞察を与えてくれます
- FRBの環境を理解することは 起源を解明するのに不可欠です
研究 の 目的:
- FRBの偏振と周波数の関係を調べる
- ポラライゼーションデータを用いてFRBを繰り返す環境を特徴付ける.
- 観察された偏極化行動とその意味をモデル化するために.
主な方法:
- 2つの電波望遠鏡を使用して5つの反復FRBのブロードバンド極測観測を行った.
- 周波数帯の偏振特性を分析した.
- マルチパス分散と回転量 (RM) の分散 (σRM) を使用して観測された周波数依存の偏振をモデル化した.
主要な成果:
- FRBの頻度が低下する傾向が見られた.
- より高い σRM値は,増加した RM 大きさと分散時間スケールと相関しています.
- 2つの特定のFRB (20121102Aと20190520B) は,最も高い σRM を示し,コンパクトな永続的な無線源に関連しています.
結論:
- 観測された二極化行動は,複雑な天体物理環境における多経路分散と一致する.
- 超新星残骸やパルサー風の星雲のようなエネルギー源の近くにあることを示唆している.
- この発見は FRBが若い恒星集団から発生するという仮説を裏付けています
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