DocumentCode :
865447
Title :
Electrodynamic forces in stellar formation
Author :
Opher, Reuven
Author_Institution :
Inst. Astron. e Geofisico, Sao Paulo Univ., Brazil
Volume :
20
Issue :
6
fYear :
1992
fDate :
12/1/1992 12:00:00 AM
Firstpage :
877
Lastpage :
881
Abstract :
The role of electrodynamic forces in star formation is discussed. Magnetic flux and angular momentum problems in star formation are discussed. It can be shown that ambipolar diffusion is able to solve the magnetic flux problem. It is also shown that Alfven waves create a Lorentz force on the plasma. Rotation of the contracting protostar creates torsional Alfven waves. The created Lorentz force can brake the protostar sufficiently to solve the angular momentum problem. It is suggested that a Lorentz force brings in the necessary magnetic field to start the star formation process. It is also suggested that it is a Lorentz force that stops the accretion of matter in the star formation process. The magnetic fields in the star formation region are suggested to have their origin in jets emitted by galactic nuclei. The Lorentz force spreads the magnetic field out over the galaxy and into the intergalactic medium. When a cloud collapses to form a protostar, it drags a magnetic field with it. The heating of the core of the cloud creates turbulence and Alfven waves. The Alfven waves and the associated Lorentz force create a jet which blows away the excess matter
Keywords :
astrophysical jets; astrophysical plasma; interstellar magnetic fields; pre-main-sequence stars; rotating bodies; star formation; stellar winds; Alfven waves; Lorentz force; accretion; ambipolar diffusion; angular momentum; contracting protostar; core; electrodynamic forces; heating; jets; magnetic flux; plasma; stellar wind; turbulence; Clouds; Contracts; Electrodynamics; Lorentz covariance; Magnetic confinement; Magnetic fields; Magnetic flux; Masers; Optical collimators; Plasma waves;
fLanguage :
English
Journal_Title :
Plasma Science, IEEE Transactions on
Publisher :
ieee
ISSN :
0093-3813
Type :
jour
DOI :
10.1109/27.199542
Filename :
199542
Link To Document :
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