重力波源の電磁対称としてキロノヴァ
S J Smartt1, T-W Chen2, A Jerkstrand3
1Astrophysics Research Centre, School of Mathematics and Physics, Queens University Belfast, Belfast BT7 1NN, UK.
Nature
|November 3, 2017
まとめ
二重中性子星の融合は 重力波とキロノバを生成します これらの現象は重元素を放出し r-プロセスの核合成と一致する電磁信号を発生させ 鉄よりも重い元素の生成における その役割を確認します
科学分野:
- 天体物理学
- 核天体物理学
- 重力波天文学
背景:
- 重力波 (GW) は最初 二重ブラックホールの合併で検出されました
- 中性子星の合併は GW を生成し 放射性物質を放出すると予測されています
- 発射された物質は キロノヴァと呼ばれる 光る電磁信号を 発するものです
研究 の 目的:
- 双子中性子星の合体 (GW170817) と一致する電磁気気流の観測を報告する.
- 物理的なパラメータをモデル化して 理論的なキロノヴァ予測と比較する
- 中性子星の融合で生成される重元素の核合成起源を調査する.
主な方法:
- 銀河NGC 4993における一時的なイベントの観測,空間的にGW170817と一致する.
- 放出された質量,不透明性,速度,および電源を含む観測された電磁放射線の物理的なモデリング.
- 元素の組成を特定し,rプロセス核合成の予測と比較するための光譜分析.
主要な成果:
- GW170817と空間的に一致する電磁気短波 (キロノヴァ) と弱いガンマ線爆発の検出
- 物理的パラメータ (放出された質量~0.04太陽質量,低不透明度,高速度) は,青いキロノヴァの予測とほぼ一致する.
- 光の曲線の電源法則の傾き (-1.2 ± 0.3) は,r-プロセスヌクレイドからの放射性電源と一致する.
- 光スペクトルの特徴は,軽いrプロセス元素 (原子質90-140) の存在を示唆しています.
- 観察された急速な色と赤みが,ランタニドに富んだ排泄物による可能性を示しています.
結論:
- バイナリー中性子星の融合は 重力波と 放射能で動くキロノバの両方を 生み出します
- これらの合併は,鉄よりも重いrプロセス元素の重要な核合成源として確認されています.
- 観測されたキロノヴァは これらの宇宙現象で重元素の生成の 直接的な証拠を提供します
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