複雑なシアン化物によって明らかにされた原惑星円盤の彗星のような構成
Karin I Öberg1, Viviana V Guzmán1, Kenji Furuya2
1Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, Massachusetts 02138, USA.
Nature
|April 10, 2015
まとめ
メチルシアン化物 (CH3CN) を含む複雑な有機分子が,原惑星円盤で検出されました. この発見は,太陽星雲の有機的豊かさがユニークではなく,初期の恒星系にも存在していたことを示唆しています.
科学分野:
- アストロケミストリー アストロケミストリー
- 惑星科学 惑星科学
- 有機化学 オーガニック・ケミストリー
背景:
- 初期の太陽星雲には,彗星や小惑星によって地球に届いた水と有機分子が含まれていた.
- 彗星は太陽星雲の組成の原始的な記録を提供しており,シアン酸はアビオティックアミノ酸の合成に不可欠です.
- 原惑星円盤には単純な揮発性物質が発見されているが,複雑な有機分子の存在は以前は不確実であった.
研究 の 目的:
- 若い恒星MWC480を取り巻く原惑星円盤における複雑なシアン酸塩の存在と豊富さを調査する.
- これらの分子の豊富な比率を彗星で見つかったものと比較するために.
- 惑星系における初期の化学的在庫に関する意味を理解する.
主な方法:
- ラジオ天文学を用いてMWC 480周辺の原始惑星円盤の観測.
- メチルシアン化物 (CH3CN) とシアノアセチレン (HC3N) を含む特定の複合シアン化物の検出と定量化.
- ガス相豊富度比の分析と彗星データとの比較.
主要な成果:
- メチルシアン化物 (CH3CN),シアノアセチレン (HC3N),そして水素シアン化物 (HCN) がMWC 480の原惑星盤で検出されました.
- これらの窒素含有有機物のガス相豊富度比は,彗星で観測されたものと類似しています.
- この類似性は,円盤の氷期内において,複雑なシアン化物の豊富性が潜在的に高いことを示唆している.
結論:
- シアン化物のような複雑な有機分子は,原惑星円盤に存在し,より単純な揮発性物質に伴っている可能性が高い.
- 生命の起源に不可欠な太陽雲の中で観察された有機化学は,おそらく私たちのシステムに特有のものではありませんでした.
- これらの発見は,生命の構成要素が新生惑星系に共通しているという考えを裏付けている.
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