Formation and alteration of circumstellar dust from coordinated studies of experiments, analysis, and observation

2022 Fiscal Year Final Research Report

• Project/Area Number: 19H01935
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 16010:Astronomy-related
• Research Institution: The University of Tokyo
• Principal Investigator: Takigawa Aki 東京大学, 大学院理学系研究科(理学部), 准教授 (10750367)
• Project Period (FY): 2019-04-01 – 2023-03-31
• Keywords: ダスト / 実験 / 珪酸塩 / 赤外線天文学 / 宇宙塵

Outline of Final Research Achievements

For understanding the formation of interstellar and circumstellar dust, we constructed a vacuum apparatus that can simulate condensation of gases of arbitrary composition, control the condensation temperature to room temperature and liquid nitrogen temperature, and perform simultaneous condensation from two electron guns and a resistance heating gas source, and conducted oxide and silicate condensation experiments at room temperature and low temperature. In addition, particulate condensation experiments in the Al-Ca-Fe-Si-Mg-O system were conducted using an induction thermal plasma system. We measured the substrate temperature, calibrated a film thickness gauge to control the condensation rate, added an H2O gas introduction system, conducted condensation experiments using a single gas source and analyzed the condensate, and conducted condensation experiments using multiple gas sources and analyzed the condensate.

Free Research Field

宇宙鉱物学

Academic Significance and Societal Importance of the Research Achievements

非晶質珪酸塩は星周・星間ダストとして豊富に，また至る所に存在し，これまでに多くの研究があるものの，観測されるダストの特徴を物質科学的に裏付けることが難しく，依然それらの組成や構造はわかっていない．本課題で低温での実験が可能でかつ系統的に組成を変化させられる実験装置を開発し，低温から高温まで幅広い宇宙環境でのダスト形成が実験室で再現できるようになった．これにより，観測から示唆されるダスト放射・吸収の特徴を再現するために必要な非晶質星周・星間ダストの形成条件と組成が推定できるようになると期待され，天文学と鉱物学の境界分野である宇宙鉱物学の発展にとって大きな意義がある．