ミルクウェイの水素ライマン-αの拡散放射をボイジャーで測定した
Rosine Lallement1, Eric Quémerais, Jean-Loup Bertaux
1Galaxies, Etoiles, Physique, Instrumentation (GEPI), Observatoire de Paris, CNRS, Université Paris Diderot, Place Jules Janssen, Meudon, France. rosine.lallement@obspm.fr
Science (New York, N.Y.)
|December 7, 2011
まとめ
ボイジャー宇宙船は,かつて太陽の光に隠されていた,ミルキーウェイの水素ライマン・アルファ (Lyα) 放射を検出しました. この画期的な発見は,遠くの銀河の恒星形成と放射伝達の理解を助けます.
科学分野:
- 天文学と天体物理学について
- コスモロジー・コスモロジーとは
- 銀河系天文学 銀河系天文学
背景:
- 水素ライマンアルファ (Lyα) 放射は,銀河の恒星形成の重要な指標である.
- ミルクウェイのLyα放射は,太陽のLyα輝き (H輝き) による圧倒的な前景汚染により,以前は検出されませんでした.
- ヘリオスフィアの境界は,Lyα放射線の局所的な源に影響する.
研究 の 目的:
- 銀河系からの拡散水素ライマン・アルファ (Lyα) 放射を検知し,特徴づけること.
- 局所的なH光干渉の課題を克服するために.
- 銀河におけるLyα放射伝達のモデルに観測的制約を与える.
主な方法:
- ホリオスフィアから出ているボイジャー宇宙船の紫外線スペクトログラフを利用した.
- 銀河のLyαのより明確な検出のために,H光からの干渉を軽減しました.
- 測定された表面の明るさと,恒星形成地域からの推定Lyα脱出分数.
主要な成果:
- 銀河系からの拡散型Lyα放射を成功裏に検出しました.
- 近くの恒星形成地域に向けて,表面の明るさが3〜4レイリーで測定されています.
- 明るいH II領域から約3%のLyα脱出分子が決定され,高い空間的変動性を示しています.
結論:
- ミルクウェイのLyα放射の検出は,新しい観測基準を提供します.
- これらの発見は,外部の銀河におけるLyα放射伝達の理論モデルを洗練します.
- Lyα放射の理解は,銀河の進化と恒星形成率の解釈に不可欠です.
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