Origin of misalignments

Protostellar jet, outflow, circumstellar disc, and magnetic field

Shingo Hirano, Masahiro Machida

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

Recent observations uncover various phenomena around the protostar such as misalignment between the outflow and magnetic field, precession of the jet, and time variability of the ejected clumps, whose origins are under debate. We perform a three-dimensional resistive magnetohydrodynamics simulation of the protostar formation in a star-forming core whose rotation axis is tilted at an angle 45. with respect to the initial magnetic field, in which the protostar is resolved with a spatial resolution of 0.01 au. In low-dense outer region, the prestellar core contracts along the magnetic field lines due to the flux freezing. In high-dense inner region, on the other hand, the magnetic dissipation becomes efficient and weakens the magnetic effects when the gas number density exceeds about 1011 cm -3 Then, the normal direction of the flattened disc is aligned with the angular momentum vector. The outflow, jet, and protostellar ejection are driven from different scales of the circumstellar disc and spout in different directions normal to the warped disc. These axes do not coincide with the global magnetic field direction and vary with time. This study demonstrates that a couple of misalignment natures reported by observations can be simultaneously reproduced only by assuming the star-forming core rotating around a different direction from the magnetic field.

Original languageEnglish
Pages (from-to)4667-4674
Number of pages8
JournalMonthly Notices of the Royal Astronomical Society
Volume485
Issue number4
DOIs
Publication statusPublished - Mar 13 2019

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misalignment
outflow
protostars
magnetic field
magnetic fields
stars
magnetohydrodynamic simulation
magnetic effects
precession
clumps
magnetohydrodynamics
ejection
angular momentum
freezing
dissipation
spatial resolution
gases
gas
simulation

All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science

Cite this

Origin of misalignments : Protostellar jet, outflow, circumstellar disc, and magnetic field. / Hirano, Shingo; Machida, Masahiro.

In: Monthly Notices of the Royal Astronomical Society, Vol. 485, No. 4, 13.03.2019, p. 4667-4674.

Research output: Contribution to journalArticle

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