シャピロの遅延を用いて測定された2太陽質量の中性子星
P B Demorest1, T Pennucci, S M Ransom
1National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, Virginia 22093, USA. pdemores@nrao.edu
Nature
|October 29, 2010
まとめ
中性子星には,宇宙で最も密度の高い物質が含まれています. 太陽の質量の1.97倍の巨大な中性子星が発見され,異質物質理論は排除され,強い相互作用するクォークが示唆されました.
科学分野:
- * 天体物理学
- * 核物理学について
- * 一般相対性理論
背景:
- * 中性子星は観測可能な物質の中で最も密度が高いもので,構成や性質は不明です.
- * 中性子星の質量と半径を測定することは,状態方程式を制約し,理論モデルをテストするために重要です.
- * 過去の質量測定では,異質物質の組成を排除するには不十分でした.
研究 の 目的:
- *シャピロの遅延を用いて中性子星の質量を正確に測定する.
- * 中性子星内の物質の状態方程式を制約する.
- * ニュートロン星の組成に関する理論モデルをテストし,その中にはエキゾチック物質の候補物も含まれます.
主な方法:
- * バイナリミリ秒パルサーJ1614-2230.0のラジオタイミング観測を利用した.
- *時空の曲折によって引き起こされる一般相対論的効果であるシャピロの遅延シグネチャーを分析した.
- * 中性子星とその二重相伴星の質量を高精度で推論した.
主要な成果:
- * J1614-2230の中性子星の質量は,太陽の質量1.97 ± 0.04であると決定しました.
- *この質量測定は,ハイパーオンやボゾン凝縮物を含む状態のほぼすべての提案された方程式を除外しています.
- *この発見は,クォーク物質がそのような巨大な恒星に存在するならば,クォークは強く相互作用しているに違いないということを暗示しています.
結論:
- * 巨大な中性子星の発見は,超密度の高い物質の組成に関する既存の理論に異議を唱える.
- *この結果は,ハイパロンやボゾン凝縮物などの異様な非核物質成分を持つモデルを強く否定しています.
- *データは,クォーク物質が存在する場合,強い相互作用を示し,フリークォーク状態を排除することを示唆しています.
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