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磁気力が強く,速く回転する白矮星.月と同じくらい小さい
Ilaria Caiazzo1, Kevin B Burdge2, James Fuller2
1Division of Physics, Mathematics and Astronomy, California Institute of Technology, Pasadena, CA, USA. ilariac@caltech.edu.
Nature
|July 1, 2021
まとめ
研究者らは,融合によって生じた極限白矮星ZTF J190132.9+145808.7を発見しました. この急速に回転する 強い磁気を持つ星は 半径がチャンドラセカルの限界に近いので 独特の冷却過程を示唆しています
科学分野:
- 天文学と天体物理学
- 星の進化について
- コンパクトオブジェクト
背景:
- 白い矮星は8太陽質量未満の恒星の 進化の最終段階です
- 白い矮星は,重力相互作用が合併につながる二進体系で頻繁に観測されます.
- 合併はタイプIaの超新星や 巨大な白矮星の残骸を 生み出す可能性があります
研究 の 目的:
- 極度の白矮星の発見と特徴を報告する
- 白い矮星が 星同士の融合によって形成される性質を 調べるために
- 高密度で磁気化された恒星の残骸で起こる 物理的プロセスを理解する
主な方法:
- 観測天文学は,高度な望遠鏡を用いて天体の検出と分析を行う.
- 磁場強度や回転周期などの恒星特性を決定するスペクトル分析.
- 恒星の半径と質量を制限するための光度測定
主要な成果:
- 白い矮星ZTF J190132.9+145808.7が発見されました
- 測られた回転期間は6.94分.
- 観測された表面磁場強度は600〜900メガガウスです.
- 恒星の半径は月よりもわずかに大きいので,チャンドラセカルの限界に近い質量を示唆しています.
結論:
- 観測された性質は,ZTF J190132.9+145808.7が白矮星合併の残骸であることを示唆している.
- 急速な回転と高い磁場を含む星の極端な特徴は 合併誘発のダイナモプロセスと一致しています
- 高い密度が,ウルカプロセスを通して冷却を誘導する.
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