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アンドロメダ銀河の周りを回っている,渦巻く矮星銀河の広大で薄い平面
Rodrigo A Ibata1, Geraint F Lewis, Anthony R Conn
1Observatoire Astronomique de Strasbourg, 11 rue de l'Université, F-67000 Strasbourg, France. rodrigo.ibata@astro.unistra.fr
Nature
|January 4, 2013
まとめ
アンドロメダの周りを回っている矮小衛星銀河は,非常に薄い平面構造に配置されています. これらの衛星銀河は,同じ軌道方向を共有し,標準的な宇宙学モデルに挑戦しています.
科学分野:
- 天文学と天体物理学について
- コスモロジー・コスモロジーとは
背景:
- 矮小衛星銀河は,初期の宇宙構造の残骸である.
- 以前の研究では,銀河系周辺の矮星銀河の非同位圏分布と平面群が示唆されていた.
- いくつかの分析では,そのような平面分布は標準宇宙学と矛盾していると主張しています.
研究 の 目的:
- アンドロメダ銀河 (M31) の周りの矮星衛星銀河の空間分布と動態を調査する.
- アンドロメダの集団の中に,平面的な衛星のサブグループが存在するかどうかを判断する.
- 標準的な宇宙学モデルからの予測と発見を比較する.
主な方法:
- M31.1.の周りを回っている矮星衛星銀河に関する既存のデータの分析
- 衛星群の直径と厚さを含む空間分布の検討.
- 放射速度測定を用いて軌道動力学と角運動量を評価する.
主要な成果:
- M31の周りの矮星衛星の有意な平面的なサブグループを発見し,人口の約半分を占めている.
- この平面構造は広大で (直径は少なくとも400 kpc) にもかかわらず,非常に薄い (分散度 <14.1 kpc).
- この平面内の衛星は一貫した回転を示し,軌道運動と角運動量方向の同じ感覚を共有します.
結論:
- M31の矮星衛星の特定された平面的なサブグループは,共通のダイナミックな軌道特性を示しています.
- この発見は,衛星銀河系システムにおける一貫した構造の有力な証拠を提供します.
- この平面が天の川の極と銀河間ベクトルと並ぶことは,大規模な構造の潜在的影響を示唆しています.
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