銀河NGC 253の恒星形成は,星爆発による分子風によって抑制されています
Alberto D Bolatto1, Steven R Warren, Adam K Leroy
1Department of Astronomy, Laboratory for Millimeter-wave Astronomy, and Joint Space Institute, University of Maryland, College Park, Maryland 20742, USA. bolatto@astro.umd.edu
Nature
|July 27, 2013
まとめ
巨大な銀河は銀河の風によって稀である. 新しい観測により,NGC 253の冷たい分子ガスの流出が明らかになり,これらの風が恒星形成と銀河の成長を調節することを示しています.
科学分野:
- 天体物理学 天体物理学
- 銀河の進化 銀河の進化 銀河の進化
- スター・フォーメーション
背景:
- 巨大な銀河の不足は,しばしば銀河の風と関連付けられています.
- イオン化された風は目に見えるが,放出された質量のほとんどは,より冷たい原子と分子相にある可能性が高い.
- 風の中で分子ガスの引き寄せを観測するには,高い空間解像度とスケールを超えた感度が必要です.
研究 の 目的:
- 銀河の風の冷たい分子成分を調査するために.
- 分子ガス,膨張する殻,およびイオン化された風との関係を決定するために.
- 近くのスターバースト銀河の分子流出率を定量化するために.
主な方法:
- 近くの星爆発銀河NGC 253.3の高解像度 (50パーセック) の観測.
- 超平面的分子ガスと,そのHαフィラメントとの関係を追跡する.
- スターバースト領域内の分子殻を分析する.
主要な成果:
- NGC 253の超平面分子ガスは50パーセル解像度で観測されました.
- 分子外流は,Hαフィラメントと膨張している殻と密接に関連していることが判明しました.
- 分子流出率は>3で,おそらく年間約9太陽質量であることが判明しました.
結論:
- スターバーストによる風は,恒星形成を制限することで,銀河の進化に大きな影響を与える.
- 質量流出率と恒星形成率の比率は少なくとも1であり,強力なフィードバックを示唆しています.
- これらの発見は,巨大な銀河の成長を調節するメカニズムに関する重要な洞察を提供します.
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