Unveiling the planet formation by ALMA polarization observations

2023 Fiscal Year Final Research Report

• Project/Area Number: 18K13590
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 16010:Astronomy-related
• Research Institution: National Astronomical Observatory of Japan
• Principal Investigator: Kataoka Akimasa 国立天文台, 科学研究部, 助教 (70749308)
• Project Period (FY): 2018-04-01 – 2024-03-31
• Keywords: 惑星形成 / 電波観測 / 偏光

Outline of Final Research Achievements

In this study, we aimed to constrain the growth process of dust, which forms the basis of planets, using a new method of millimeter-wave polarization of protoplanetary disks observed with ALMA. As a result, we demonstrated that the polarization in the submillimeter wavelength can be explained by the self-scattering mechanism in many protoplanetary disks. Furthermore, by advancing modeling to resolve inconsistencies with multi-wavelength polarization observations and spectral analysis, we successfully showed that the solid material in protoplanetary disks is composed of dust aggregates with many voids. This result supports the planet formation scenario through highly porous dust aggregates, which had been theoretically suggested, and successfully promotes planet formation research by exploring both theoretical and observational aspects.

Free Research Field

天文学

Academic Significance and Societal Importance of the Research Achievements

本成果は、日本が重要な一角を担う国際共同望遠鏡ALMAにおいて、惑星形成分野における科学成果を大きくリードすることにつながった。本成果は1970年代から太陽系形成論としてリードしてきた惑星形成理論を、更に観測からもリードし、世界における日本のプレゼンスを示した結果と考えている。惑星形成理論においては、2007年以降日本グループによって指摘されてきた高空隙ダストアグリゲイトを観測的に示した初めての成果となっており、その学術的意義は大きいと言える。