銀河系内部の数パーセックに広がった硬いX線放射
Kerstin Perez1, Charles J Hailey2, Franz E Bauer3
11] Columbia Astrophysics Laboratory, Columbia University, 550 West 120th Street, Room 1027, New York, New York 10027, USA [2] Haverford College, 370 Lancaster Avenue, KINSC L109, Haverford, Pennsylvania 19041, USA.
Nature
|May 1, 2015
まとめ
天文学者は,銀河の中心部で明確な硬いX線放射を発見しました. この発見は,現在の星進化モデルと,射手座A*近くの宇宙線生成モデルに異議を唱えている.
科学分野:
- 天体物理学 天体物理学
- 高エネルギー天文学 高エネルギー天文学
- 銀河学研究センター研究
背景:
- 銀河の中心には,射手座A*の近くにある若くて巨大な恒星の謎めいた集団がある.
- 以前の研究では,ソフトなX線源が主に白矮星を集積していることを示していた.
- 拡散した硬いX線放射の観測は,儀器解像度によって制限されていました.
研究 の 目的:
- 改善された空間解像度で銀河の中心内部のハードX線放射を調査する.
- この硬いX線構成要素の性質と起源を特徴づけるために.
主な方法:
- 20~40キロエレクトロンボルトのエネルギー範囲のサブカル分分解像度画像を使用しました.
- 銀河中心の中央4 × 8パーセック内の分散した硬いX線放射を分析した.
主要な成果:
- 中央の4×8パーセックに独特の硬いX線構成要素の存在が報告されました.
- この硬いX線放射は,柔らかいX線源よりも,銀河の中心に向かって急激にピークしていることが観察されました.
結論:
- この発見は,白矮星が増加し,低質量X線バイナリー星,ミリ秒パルサー,または粒子の流出など,より大規模な白矮星集団が存在する可能性を示唆している.
- これらの解釈は,恒星の進化,二重星形成,銀河中心の宇宙線生成に関する既存の理論に重大な課題をもたらす.
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