TY - JOUR
T1 - Spiral-arm resonance in galactic dynamos
AU - Chiba, Masashi
N1 - Funding Information:
The author is gratefulto Professor Tosa for his continual encouragement. Numerical calculations were performed on ACOS SX2 system at the Computer Center of Tohoku University.
Publisher Copyright:
© 1991 Oxford University Press. All rights reserved.
PY - 1991
Y1 - 1991
N2 - We study further properties of the resonance of galactic dynamos under the influence of galactic density waves. Two-dimensional numerical calculations are performed to elucidate the characteristic structure and evolution of the excited magnetic fields in a galactic disc. Models subject to spiral-arm perturbations of the α-effect are considered as well as those with perturbations of the gaseous velocity fields. It is shown that in the state of complete resonance, the magnetic fields exhibit a steady growth of energy without any oscillations. The whole pattern of magnetic fields remains unchanged with time, but propagates just with the imposed disturbances parallel to the galactic plane. The field structure excited is found to be largely influenced by the spatial form of disturbances in the velocity fields and α-effects; for example, the wavelength of excited fields is just twice that of density waves.
AB - We study further properties of the resonance of galactic dynamos under the influence of galactic density waves. Two-dimensional numerical calculations are performed to elucidate the characteristic structure and evolution of the excited magnetic fields in a galactic disc. Models subject to spiral-arm perturbations of the α-effect are considered as well as those with perturbations of the gaseous velocity fields. It is shown that in the state of complete resonance, the magnetic fields exhibit a steady growth of energy without any oscillations. The whole pattern of magnetic fields remains unchanged with time, but propagates just with the imposed disturbances parallel to the galactic plane. The field structure excited is found to be largely influenced by the spatial form of disturbances in the velocity fields and α-effects; for example, the wavelength of excited fields is just twice that of density waves.
UR - http://www.scopus.com/inward/record.url?scp=1542727276&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=1542727276&partnerID=8YFLogxK
U2 - 10.1093/mnras/250.4.769
DO - 10.1093/mnras/250.4.769
M3 - Article
AN - SCOPUS:1542727276
VL - 250
SP - 769
EP - 779
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
SN - 0035-8711
IS - 4
ER -