Investigation into Stellar Mass Loss Based on Three-Dimensional Multiwavelength Spectroscopic Data of Galactic Planetary Nebulae

2023 Fiscal Year Final Research Report

• Project/Area Number: 19K03914
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 16010:Astronomy-related
• Research Institution: Kyoto University
• Principal Investigator: OTSUKA Masaaki 京都大学, 理学研究科, 特定助教 (70399286)
• Project Period (FY): 2019-04-01 – 2024-03-31
• Keywords: 惑星状星雲 / ダスト減光 / 元素組成 / 三次元面分光

Outline of Final Research Achievements

I investigated the spatial distribution of gas and dust in Galactic planetary nebulae based on optical three-dimensional spectra in order to quantitatively unveil stellar mass loss in low- to intermediate-mass stars. I obtained the following important findings: (1) The spatial distribution of gas and dust masses is not uniform. Both masses are concentrated along the equator. This indicates that anisotropic mass-loss during the AGB star phase forms the equatorial torus, determining the directionality of subsequent mass-loss and consequently forming non-spherical shaped nebulae. (2) The spatial gas-to-dust mass ratio varies significantly within the nebula. (3) The spatial distribution of elemental abundances reflects the formation history of the nebula and the evolutionary history of the central star.

Free Research Field

恒星物理学

Academic Significance and Societal Importance of the Research Achievements

本研究は、惑星状星雲におけるガスとダストの物理量空間分布を可視三次元分光観測のみで明らかにし、中小質量星の質量放出メカニズムと惑星状星雲の形成過程を定量的に解明した点で学術的新規性がある。独自に開発した解析手法は、惑星状星雲に限らず輝線を発する天体すべてに適用可能である点で技術的新規性がある。また、星と宇宙の進化が生命の起源にどう関係しているのかを考える機会を提供した点で社会的意義がある。