Exploration of universal star and planet formation processes through the studies of chemical structures in protoplanetary disks and exoplanetary atmospheres

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K22376
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Multi-year Fund
• Review Section: 0204:Astronomy, earth and planetary science, and related fields
• Research Institution: Institute of Physical and Chemical Research
• Principal Investigator: Notsu Shota 国立研究開発法人理化学研究所, 開拓研究本部, 特別研究員 (40874649)
• Project Period (FY): 2020-09-11 – 2023-03-31
• Keywords: 原始惑星系円盤 / アストロケミストリー / 星・惑星形成 / 原始星 / 太陽系外惑星 / スノーライン / ALMA / X線

Outline of Final Research Achievements

The purpose of this research project is to develop a realistic theory of planet formation based on the latest observations and calculations of the chemical structure of the protostellar envelopes, protoplanetary disks, and exoplanetary atmospheres. We investigated the effects of X-ray emission from the central protostar on the chemical evolution of the protostellar envelope and disk, and chemical evolution (such as evolution fo snowline positions and distribution of elementral abundance ratios) in the disk where a shadow structure is formed due to dust concentration beyond the water snowline, through detailed chemical reaction network calculations. In parallel, we conducted molecular emission line observations and discussion for future observations to identify snowline positions and molecular abundance distributions in protostellar objects and disks for infrared and submillimeter wavelengths.

Free Research Field

星・惑星形成

Academic Significance and Societal Importance of the Research Achievements

原始星段階から円盤散逸期までの物理構造と化学構造の時間進化を同時に扱うモデルの構築を進める中で、最新の観測結果による裏付けも踏まえた現実的な円盤進化・惑星形成の描像の理解に寄与した。また、原始星天体および原始惑星系円盤のスノーライン位置や分子組成分布の同定を目指した分子輝線観測(ALMA, 野辺山45m)を進めるのみならず、赤外線・サブミリ波の将来望遠鏡サイエンス検討(GREX-PLUS, ngVLA, LST等)にも大きく貢献した。さらに、円盤化学構造計算の結果は、彗星・小惑星等における物質科学的な情報の理解にも役立つことが見込まれ、高い波及効果が期待される。