ダイナミックに若い 混乱した 銀河の円盤
T Antoja1, A Helmi2, M Romero-Gómez3
1Institut de Ciències del Cosmos, Universitat de Barcelona (IEEC-UB), Barcelona, Spain. tantoja@fqa.ub.edu.
Nature
|September 21, 2018
まとめ
銀河系
科学分野:
- 天文学と天体物理学
- 銀河の力学
背景:
- 銀河系の円盤の進化は 棒や渦巻き腕や衛星銀河によって 影響を受けています
- ダイナミックなプロセスは 円盤の恒星移動,加熱,速度構造の変化を引き起こします.
- 以前の研究では 運動構造と均衡モデルからの偏差が検出されました
研究 の 目的:
- 銀河の円盤の600万個の星を分析する
- 下部構造を特定し,過去の動的混乱を推論する.
主な方法:
- 600万個の星の空間座標と速度を分析した.
- "スナック・シェル"や"リッジ"のようなフェーズ・スペース・サブストラクチャの識別
主要な成果:
- 段階空間分布は 異なる基底構造を示しています
- 3億から9億年前に 重要な乱れが発生しました
- このタイミングは 射手座の矮星銀河の 円周回路と一致します
結論:
- 銀河の円盤は動的に若く 安定した状態ではありません
- 円盤を時間独立で軸対称としてモデル化することは不正確です.
- 過去の衛星銀河との相互作用が 円盤の進化を大きく形作っています
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