近くの渦巻き銀河M33の,日食する二重星系にある,太陽質量15.65のブラックホール
Jerome A Orosz1, Jeffrey E McClintock, Ramesh Narayan
1Department of Astronomy, San Diego State University, 5500 Campanile Drive, San Diego, California 92182-1221, USA. orosz@sciences.sdsu.edu
Nature
|October 19, 2007
まとめ
研究者らは,M 33 X-7系で異常な質量の恒星ブラックホールを発見した. この発見は恒星の進化モデルに異議を唱え,二重星系進化の過程で質量損失が少ないことを示唆している.
科学分野:
- 天体物理学 天体物理学
- 恒星の進化について
- X線天文学 X線天文学
背景:
- 恒星質量のブラックホールは,X線バイナリ系で典型的に見られる.
- 既存の恒星の進化モデルでは,近い二重星系で太陽の質量10倍を超えるブラックホールを説明するのに苦労しています.
- 既知の大質量恒星ブラックホールのほとんどは,太陽の10倍の質量を持っています.
研究 の 目的:
- M 33 X-7 システムのブラックホールの質量を報告するために.
- 巨大なブラックホールが恒星の進化と二重星系ダイナミクスに及ぼす影響を調査する.
- 観測された質量を理論的モデルと調和させる.
主な方法:
- M 33 X-7 二重星系における伴星の動力の分析.
- エクリプスする二重星系M 33 X-7のデータを活用して.
- 観測データを恒星の進化モデルと比較する.
主要な成果:
- M 33 X-7のブラックホールの質量は,太陽の質量 (15.65 +/- 1.45) のブラックホールの質量と決定されました.
- M 33 X-7は,ブラックホールを含む唯一の既知の日食バイナリーシステムです.
- 先祖星は,ヘリウム融合後のまで,外側の封筒を保持した可能性が高い.
- 共通エンベロープフェーズは,通常モデルで想定されるよりも,質量損失がかなり少ない必要がありました.
結論:
- このような巨大なブラックホールの存在は,恒星の進化の理解を修正する必要があり,特に一般的な封筒段階での質量損失を修正する必要があります.
- M 33 X-7システムは,二重星系における巨大な恒星の進化のモデルを精錬するための重要な観測的制約を提供します.
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