ROSATは,ドラコ星雲の1/4-keVの拡散背景にX線影を検出しました
まとめ
ROSATのX線影は,密度の高いH I雲を明らかにし,その向こうから有意な宇宙拡散背景放射が発生していることを示唆しています. これは,銀河の平面から遠く離れた場所に,不規則な熱い銀河のコロナが存在する可能性があることを示唆しています.
科学分野:
- X線天文学X線天文学とは
- コスミック・ディフューズ・バックグラウンド・放射線
- 銀河の構造 銀河の構造
背景:
- 1/4キロ電子ボルト (keV) の宇宙拡散背景 (CDB) は,星間介質の洞察を提供します.
- 以前の観測では,低エネルギーX線吸収特性の詳細なマッピングが欠けていました.
- 銀河系の熱いガスの分布を理解することは極めて重要です.
研究 の 目的:
- ROSATデータを用いて,1/4-keVの宇宙拡散背景で検出された影を調査する.
- X線影を引き起こす吸い込み物体の性質と位置を決定する.
- 銀河の構造と熱いガス分布への影響を調査する.
主な方法:
- ロエンツゲン衛星 (ROSAT) のX線望遠鏡からのデータを活用.
- 1/4-keVのX線放射の空間的分布と強度を分析する.
- 中性水素 (H I) の雲データと速度コンポーネントとX線特性を相関させる.
主要な成果:
- 1/4-keV CDBで深いX線影が検出され,H I 雲と一致しています.
- 影の深さは,少なくとも50%のオフ・クラウド・フルースが,クラウドの向こうから発生することを示しています.
- H I速度の分析は,雲とドラコ星雲 (約600パーセク) を結び付け,遠隔のX線放射 (>銀河平面から400パーセク) を示唆している.
結論:
- 観測されたX線影は,離散的なH I. 雲によって引き起こされています.
- 重要な1/4-keVのX線放射は,銀河平面から遠く,ドラコ星雲の視線に沿って存在する.
- この遠くの放射は,バラバラな熱い銀河のコロナを示し,さらなる調査が必要である可能性があります.
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