SN2014Jからの初期の56Ni崩壊ガンマ線は,異常な爆発を示唆しています
Roland Diehl1, Thomas Siegert2, Wolfgang Hillebrandt3
1Max-Planck-Institut für Extraterrestrische Physik, Giessenbachstrasse 1, D-85741 Garching, Germany rod@mpe.mpg.de.
まとめ
超新星SN2014Jにおける放射性ニッケル-56の早期発見は,非対称な爆発を示唆している. この発見は,タイプIア超新星に関する標準モデルに異議を唱え,ニッケル-56.6の不均一な分布を示している.
科学分野:
- * 天体物理学
- * 核天体物理学
背景:
- * Ia型超新星は,炭素-酸素白矮星を含むバイナリ系から発生する.
- *これらの爆発は,通常,放射性ニッケル-56の約0.5太陽質量の放射性ニッケル-56を生成し,通常は噴射物の中に深く埋め込まれています.
研究 の 目的:
- *超新星SN2014Jにおける放射性ニッケル-56の崩壊によるガンマ線の初期の放射を調査する.
- * 初期のニッケル-56検出が爆発不対称性とタイプIア超新星標準モデルに与える影響を理解する.
主な方法:
- *158キロ電子ボルトと812キロ電子ボルトのガンマ線が検出され,ニッケル-56の崩壊を示唆しています.
- *検出のタイミングは爆発後約20日,予想よりかなり早い.
主要な成果:
- * 爆発後約8.8日後に,ニッケル-56の分解から初期のガンマ線信号が観測されました.
- * 予想されるニッケル56の総量の約10%に相当する流量レベルが検出されましたが,これは典型的な数週間の時間スケールよりもはるかに早いものです.
- * 早期検出は,非球形の爆発メカニズムとニッケル-56.6の外向きの分布を暗示しています.
結論:
- * SN2014Jにおけるニッケル-56の早期と空間的に分布した検出は,タイプIア超新星における球形の対称性に関する仮定に異議を唱える.
- * 可能性のあるメカニズムは,伴星からヘリウムが蓄積され,超新星を誘発し,ニッケル-56を不均等に分配する爆発ベルトを形成することです.
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