First MHD simulation of collapse and fragmentation of magnetized molecular cloud cores

Masahiro N. Machida, Kohji Tomisaka, Tomoaki Matsumoto

Research output: Contribution to journalArticle

55 Citations (Scopus)

Abstract

This is the first paper about fragmentation and mass outflow in molecular clouds by using three-dimensional magnetohydrodynamical (MHD) nested-grid simulations. The binary star formation process is studied, paying particular attention to the fragmentation of a rotating magnetized molecular cloud. We assume an isothermal rotating and magnetized cylindrical cloud in hydrostatic balance. Non-axisymmetric as well as axisymmetric perturbations are added to the initial state and the subsequent evolutions are studied. The evolution is characterized by three parameters: the amplitude of the non-axisymmetric perturbations, the rotation speed and the magnetic field strength. As a result, it is found that non-axisymmetry hardly evolves in the early phase, but begins to grow after the gas contracts and forms a thin disc. Disc formation is strongly promoted by the rotation speed and the magnetic field strength. There are two types of fragmentation: that from a ring and that from a bar. Thin adiabatic cores fragment if their thickness is less than 1/4 of the radius. For the fragments to survive, they should be formed in a heavily elongated barred core or a flat round disc. In the models showing fragmentation, outflows from respective fragments are found as well as those driven by the rotating bar or the disc.

Original languageEnglish
Pages (from-to)L1-L5
JournalMonthly Notices of the Royal Astronomical Society
Volume348
Issue number1
DOIs
Publication statusPublished - Feb 11 2004

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molecular clouds
fragmentation
simulation
fragments
outflow
perturbation
magnetic field
field strength
hydrostatics
binary stars
magnetic fields
star formation
grids
gas
radii
rings
gases
speed

All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science

Cite this

First MHD simulation of collapse and fragmentation of magnetized molecular cloud cores. / Machida, Masahiro N.; Tomisaka, Kohji; Matsumoto, Tomoaki.

In: Monthly Notices of the Royal Astronomical Society, Vol. 348, No. 1, 11.02.2004, p. L1-L5.

Research output: Contribution to journalArticle

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