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Hyperpolarized Xenon for NMR and MRI Applications
Published on: September 6, 2012
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2種類の超新星によって生成されたX線パルサーの2つの集団
Christian Knigge1, Malcolm J Coe, Philipp Podsiadlowski
1University of Southampton, School of Physics and Astronomy, Southampton SO17 1BJ, UK. c.knigge@soton.ac.uk
Nature
|November 15, 2011
まとめ
科学者たちは,Be/X線バイナリクラスの中で,異なる超新星型から発生した可能性がある2つの異なる中性子星のグループを発見しました. 電子捕獲超新星は,より短いスピンと軌道周期とより低い離心率を持つ中性子星を形成しているようです.
科学分野:
- 天体物理学 天体物理学
- 恒星の進化について
- 中性子星の形成とは
背景:
- 中性子星は主に鉄核の崩壊による超新星と電子捕獲超新星によって形成されます.
- この2つの異なる形成チャネルによって生成された中性子星の区別は困難でした.
- X線パルサーの一種であるビー/X線バイナリー星は,伴星から形成される中性子星の宿主である.
研究 の 目的:
- ビー/X線バイナリクラスが,異なる超新星形成経路に関連した異なる亜集団を含むかどうかを調査する.
- これらの潜在的なサブ集団間の観察可能な差異を特定する.
主な方法:
- Be/X線バイナリにおける中性子星の特徴的なスピン周期,軌道周期,軌道離心率の分析.
- これらのパラメータを統計的に比較して,異なるグループを特定します.
主要な成果:
- 中性子星の宿主であるX線パルサー (Be/X線バイナリ) の大きなクラスは,2つの異なる亜集団で構成されていることが判明しました.
- これらの亜集団は,特徴的なスピン周期,軌道周期,軌道特異度によって異なる.
- 電子捕捉超新星は,短期のスピン周期,短い軌道周期,低離心率を示すシステムと好ましく関連付けられています.
結論:
- ビー/X線バイナリーの観測された亜集団は,2つの異なる超新星形成チャネルに相当する可能性がある.
- 電子捕獲超新星は,好ましくは,特定の性質 (より短い周期,より低い離心率) を有する中性子星を生成する可能性があります.
- スピン周期分布の対数における明確な分割は予想外であり,さらなる理論的説明が必要である.
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