Density waves in the disks of two spiral galaxies

1976 ◽  
Vol 206 ◽  
pp. L11 ◽  
Author(s):  
S. E. Strom ◽  
K. M. Strom ◽  
E. B. Jensen
Keyword(s):  
Spiral Galaxies ◽  
Density Waves

Density waves in the outer disk of spiral galaxies

2010 ◽  
Author(s):  
G. Bertin ◽  
N. C. Amorisco ◽  
Giuseppe Bertin ◽  
Franca De Luca ◽  
Giuseppe Lodato ◽  
...  
Keyword(s):  
Spiral Galaxies ◽  
Density Waves ◽  
Outer Disk

Fast and Slow Density Waves in Magnetized Spiral Galaxies

1998 ◽  
Vol 493 (1) ◽  
pp. 102-120 ◽  
Author(s):  
Yu‐Qing Lou ◽  
Zuhui Fan
Keyword(s):  
Spiral Galaxies ◽  
Density Waves

scholarly journals Fast magnetohydrodynamic density waves in spiral galaxies

1999 ◽  
Vol 308 (1) ◽  
pp. L1-L5 ◽  
Author(s):  
Yu-Qing Lou ◽  
J. L. Han ◽  
Zuhui Fan
Keyword(s):  
Spiral Galaxies ◽  
Density Waves

Multiwavelength Structural Manifestations of Fast Magnetohydrodynamic Density Waves in Spiral Galaxies

2002 ◽  
Vol 567 (1) ◽  
pp. 289-293 ◽  
Author(s):  
Yu‐Qing Lou ◽  
Wilfred M. Walsh ◽  
J. L. Han ◽  
Zuhui Fan
Keyword(s):  
Spiral Galaxies ◽  
Density Waves

Star-gas density waves in spiral galaxies

1986 ◽  
Vol 309 ◽  
pp. 496 ◽  
Author(s):  
Stephen H. Lubow ◽  
Lennox L. Cowie ◽  
Steven A. Balbus
Keyword(s):  
Spiral Galaxies ◽  
Density Waves ◽  
Gas Density

scholarly journals Large-Scale Galactic and Intergalactic Magnetic Fields

1990 ◽  
Vol 140 ◽  
pp. 90-94
Author(s):  
M. Fujimoto ◽  
T. Sawa
Keyword(s):  
Magnetic Fields ◽  
Radio Emission ◽  
Faraday Rotation ◽  
Large Scale ◽  
Spiral Galaxies ◽  
Radio Galaxies ◽  
Density Waves ◽  
Dynamo Theory ◽  
Spiral Density Waves

Large-scale axisymmetric and bisymmetric spiral (ASS and BSS) structures are found of magnetic fields in spiral galaxies by measuring the Faraday rotation of polarized radio emission. Dynamo theory is introduced to explain the field structures, and strong magnetogravitational interaction is suggested to occur between the BSS magnetic fields and spiral density waves. Up-to-date data about the rotation measures RM and redshifts z of QSOs and distant radio galaxies are given for discussing large-scale intergalactic magnetic fields.

scholarly journals Swing Excitation of Galactic Magnetic Fields Induced by Spiral Density Waves

1990 ◽  
Vol 140 ◽  
pp. 131-132 ◽  
Author(s):  
Masashi Chiba ◽  
Makoto Tosa
Keyword(s):  
Magnetic Fields ◽  
Spiral Galaxies ◽  
Field Structure ◽  
Excited Configuration ◽  
Density Waves ◽  
Galactic Magnetic Fields ◽  
Spiral Density Waves ◽  
Dynamo Wave ◽  
Field Oscillation ◽  
Armed Spiral

The generation and maintenance of galactic magnetic fields are considered when the dynamo-acted disk is perturbed by spiral density waves. The periodic change of gaseous density and shear is coupled with the field oscillation as a dynamo wave. We find the conditions for parametric resonance which increases the efficiency of dynamos. Special attention is paid to two-armed spiral galaxies, in which the BSS field structure is possibly the most effectively excited configuration owing to the present mechanism.

scholarly journals Halo Mass in Spiral Galaxies

1977 ◽  
Vol 45 ◽  
pp. 297-300 ◽  
Author(s):  
Ch. K. Terzides
Keyword(s):  
Dispersion Relation ◽  
Spiral Galaxies ◽  
Excitation Mechanism ◽  
Density Waves ◽  
Spiral Arms ◽  
S Model ◽  
Halo Population

We have solved the dispersion relation given by the theory of Lynden Bell and Kalnajs (1972) using models with spherical halos under the assumption that the halo population does not participate in the spiral arms. Especially we have studied the conditions under which the solutions of this dispersion relation reach corotation so that the excitation mechanism of the density waves due to the theory of Lynden Bell-Kalnajs is applicable. We have used as basic axisymmetric models the model of Schmidt (1965) (S-model) and the model proposed by Miyamoto and Nagai (1975) (M-model) On these models we have superimposed spherical halos so that in a sphere of radius 20 kpc there exists a given amount of mass with two different density laws: ρ as r-1and p as r-2.

THE BAR INSTABILITY REVISITED IN COSMOLOGICAL SCENARIO

1998 ◽  
Vol 13 (25) ◽  
pp. 2035-2038
Author(s):  
ANNA CURIR
Keyword(s):  
Spiral Galaxies ◽  
The Other ◽  
Density Waves ◽  
Stationary Density ◽  
Tidal Interactions ◽  
Cosmological Scenario ◽  
Hydrodynamical Simulations

About two-thirds of spiral galaxies are classified as barred: only one-third is very strongly barred (SB) and the other is classified as "intermediate" SB galaxies, i.e. galaxies with a faint bar. Bars are quasi-stationary density waves originated by swing amplification mechanisms. We use smooth-particle-hydrodynamical simulations to give insights into the role triaxiality of the halo on triggering the bar instability and to investigate how tidal interactions act on the bar evolution. We argue that the triaxiality of the primordial halo and the weight of the halo have a fundamental role in monitoring the incidence of the bar instability in spiral galaxies.

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