デュテリウム を 濃縮 し た 水 は,惑星 を 形成 する 円盤 を 彗星 や 原星 と 結びつける
John J Tobin1, Merel L R van 't Hoff2, Margot Leemker3
1National Radio Astronomy Observatory, Charlottesville, VA, USA. jtobin@nrao.edu.
Nature
|March 8, 2023
まとめ
この研究では,V883 Ori 原星盤のガス相水を直接検出し,80AUの水雪線を明らかにした. 測定した水
科学分野:
- 天文学と天体物理学
- 惑星科学
- 天体化学
背景:
- 水は惑星の形成に不可欠であり,原惑星円盤の固体物質の成長に影響を与えます.
- 水のスノーラインとHDO:H2O比率は,水の低亜鉛化温度のために十分に理解されていません.
- 以前の推定では,V883 Oriの水雪線は40-120AUであった.
研究 の 目的:
- V883 オリ原惑星円盤の ガス相水を直接検出する
- V883 オリディスクの水雪線半径とHDO:H2O比率を正確に決定する.
- 星形成の雲から惑星の体への水の継承を理解するために
主な方法:
- V883 オリディスクのHDOとH2O分子を検出するために,高度な観測技術を活用しました.
- 水の空間的分布と豊富さを測定するために分析されたスペクトルデータ.
- 円盤内のHDO:H2O比を計算した.
主要な成果:
- V883 Oriディスクのガス相水 (HDOとH2O) を直接検出した.
- 約80AUの半径で160AUまで伸びている.
- 円盤のHDO:H2O比が (2.26 ± 0.63) × 10^-3と決定され,彗星と地球の海を超えている.
結論:
- 原始惑星の円盤は 恒星形成雲から直接水を受け継いでいます
- 水は彗星のように 氷の塊に吸収され 化学的変化が最小限に抑えられます
- この発見は惑星形成の初期段階と 太陽系の水分分布について 重要な洞察を与えてくれます
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