The links between magnetic fields and filamentary clouds - III. Field-regulated mass cumulative functions
Journal article, 2020

During the past decade, the dynamical importance of magnetic fields in molecular clouds has been increasingly recognized, as observational evidence has accumulated. However, how a magnetic field affects star formation is still unclear. Typical star formation models still treat a magnetic fields as an isotropic pressure, ignoring the fundamental property of dynamically important magnetic fields: their direction. This study builds on our previous work, which demonstrated how the mean magnetic field orientation relative to the global cloud elongation can affect cloud fragmentation. After the linear mass distribution reported earlier, we show here that the mass cumulative function (MCF) of a cloud is also regulated by the field orientation. A cloud elongated closer to the field direction tends to have a shallower MCF: in other words, a higher portion of the gas is at high density. The evidence is consistent with our understanding of the bimodal star formation efficiency discovered earlier, which is also correlated with the field orientation.

ISM: magnetic fields

stars: formation

ISM: clouds

Author

Chi Yan Law

Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics

H. B. Li

Chinese University of Hong Kong

Zhuo Cao

Chinese University of Hong Kong

C. Y. Ng

The University of Hong Kong

Monthly Notices of the Royal Astronomical Society

0035-8711 (ISSN) 1365-2966 (eISSN)

Vol. 498 1 850-858

Subject Categories

Meteorology and Atmospheric Sciences

Astronomy, Astrophysics and Cosmology

Condensed Matter Physics

DOI

10.1093/mnras/staa2466

More information

Latest update

12/7/2020