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2パーセントの精度で,大マゲラン雲から日食バイナリ距離
G Pietrzyński1, D Graczyk, W Gieren
1Universidad de Concepción, Departamento de Astronomía, Casilla 160-C, Concepción, Chile. pietrzyn@astrouw.edu.pl
Nature
|March 8, 2013
まとめ
天文学者たちは,冷たい二重星による日食による二重星を用いて,大マゲラン雲までの距離を正確に測定した. これは,宇宙膨張を理解するために不可欠なハッブル定数の精度を改善します.
科学分野:
- コスモロジー・コスモロジーとは
- 天体物理学 天体物理学
- 星の天文学 星の天文学
背景:
- ハッブル定数を正確に決定することは,精密宇宙論にとって不可欠です.
- ハッブル定数の不確実性は,現在,大マゲラン雲 (LMC) までの距離によって制限されています.
- 日食バイナリーは,正確な恒星パラメータと距離測定のための貴重なツールです.
研究 の 目的:
- 大マゲラン雲 (LMC) までの距離を,より高い精度で測定する.
- 宇宙距離スケールのより信頼性の高いアンカーを提供するために.
- ハッブル定数のより正確な決定を可能にするために.
主な方法:
- 冷たく巨大な恒星で構成される,LMCの8つの長期,遅いタイプの日食バイナリーシステムを研究しました.
- バイナリコンポーネントの線形と角形のサイズを正確に測定しました.
- 熱い,初期のタイプの日食系をモデリングすることに関連する複雑さを回避しました.
主要な成果:
- 49.97 ± 0.19 (統計的) ± 1.11 (系統的) キロパーセックスの LMC 距離を導出しました.
- LMCで2.2%の距離精度を達成しました.
- この結果は,ハッブル定数の3%の決定のための堅固な基礎を提供します.
結論:
- 後期型のエクリプスバイナリーの使用は,LMC距離の決定により正確な方法を提供します.
- 改善されたLMC距離は,ハッブル恒定の計算における重要な不確実性を大幅に軽減します.
- 将来の見通しは,ハッブル恒定の測定でさらに高い精度 (2%) の可能性を示しています.
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