膨張する炭素・酸素・ネオン星の中で爆発するWC/WO星
A Gal-Yam1, R Bruch2, S Schulze2,3
1Department of Particle Physics and Astrophysics, Weizmann Institute of Science, Rehovot, Israel. avishay.gal-yam@weizmann.ac.il.
Nature
|January 13, 2022
まとめ
巨大なウルフ・ライエット星,特にヘリウム欠乏したWC/WO型は,急速に進化するトランジエントの祖先である可能性があります. SN 2019hgpの観測は,これらの星が爆発し,ブラックホールの直接的な崩壊に関する以前の理論に挑戦することを示唆しています.
科学分野:
- 天体物理学
- スター進化
- 暫定的な天文学
背景:
- 巨大な恒星とそのコンパクトな残骸 (ブラックホール,中性子星) の最終的な運命については,まだ未解決の疑問が残っています.
- 巨大な恒星は水素の封筒を失い 強力な風を持つ ウォルフ・レイエの恒星へと進化します
- ヘリウムが枯渇したWC/WO ウォルフ・レイエの星は,目に見える超新星を避け,ブラックホールに直接崩壊すると疑われています.
研究 の 目的:
- 急速に進化する変異性SN 2019hgpの祖先を調査する.
- 観測可能な超新星爆発を 生み出すことができるかどうかを判断する.
- ウルフ・レイエット星と水素/ヘリウムに乏しい超新星との関連を理解する.
主な方法:
- 爆発直後のSN 2019hgpのスペクトロスコピーを利用した観測天文学.
- 噴出物の構成と膨張速度を決定するために,放射と吸収線の特徴を分析する.
- 観測された一時的な性質と,恒星の進化と超新星の理論的モデルを比較する.
主要な成果:
- SN 2019hgpは,急速に進化するトランジエントの特徴である短い上昇時間と急速な減少を示した.
- 顕微鏡では,炭素,酸素,ネオンからの放射線と高速吸収の特徴 (> 1,500 km/s) が明らかになった.
- これらの発見は 巨大なWC/WO星からの爆発と一致します
結論:
- 巨大なウルフ・レイエット星,特にWC/WO型は,観測可能な超新星爆発の祖先である.
- 観測されたSN 2019hgpの性質は,これらの恒星が急速に進化するトランジエントにつながる可能性があるという仮説を支持する.
- ブラックホールの崩壊は 目に見える爆発なしに 起こると考えられています
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