Star Formation Study Based on Polarization and Radiation Transfer: Role of Interstellar Magnetic Field

2017 Fiscal Year Final Research Report

• Project/Area Number: 15K05032
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Astronomy
• Research Institution: National Astronomical Observatory of Japan
• Principal Investigator: Tomisaka Kohji 国立天文台, 理論研究部, 教授 (70183879)
• Co-Investigator(Kenkyū-buntansha): 町田 正博 九州大学, 理学研究院, 准教授 (10402786)
• Project Period (FY): 2015-04-01 – 2018-03-31
• Keywords: 星間磁場 / 偏波 / 星形成 / 磁気流体力学 / フィラメント / 圧力平衡 / 重力安定性

Outline of Final Research Achievements

Combining Herschel Space Observatory far infrared observations and interstellar polarization observations, it is shown molecular clouds are formed by ensembles of filaments which are perpendicularly threaded by the magnetic field. We obtained the magnetohydrostatic configuration and their maximum stable line-mass as a function of the magnetic flux per unit mass. Stability of such filament is studied with magnetohydrodynamical simulations. There exists the shortest wavelength above which the filament undergoes the gravitational instability (critical wavelength). The most unstable mode has a wavelength twice as long as the critical wavelength. The filament fragments with the most unstable wavelength and experiences runaway collapse as long as the gas is isothermal and forms a pseudo-disk which extends in the direction perpendicular to the magnetic field.

Free Research Field

シミュレーション天文学