Results 121 to 130 of about 198 (153)

ON THE FRACTION OF BARRED SPIRAL GALAXIES [PDF]

Astrophysical Journal Letters, 2010
We investigate the stellar masses of strongly barred spiral galaxies. Our analysis is based on a sample of ~14000 visually-classified nearby galaxies given in Nair & Abraham 2010(a). The fraction of barred spiral galaxies is found to be a strong function of stellar mass and star formation history, with a minimum near the characteristic mass at ...
Nair, Preethi B., Abraham, Roberto G.
exaly   +3 more sources

The stellar dynamics of spiral arms in barred spiral galaxies [PDF]

Monthly Notices of the Royal Astronomical Society: Letters, 2006
Abstract A dynamical mechanism is proposed that explains the spiral structure observed frequently as a continuation of the bars in barred spiral galaxies. It is argued that the part of the spirals attached to the bar is due to chaotic orbits. These are chaotic orbits that exhibit for long time intervals a 4:1-resonance orbital behaviour.
Panos Patsis
exaly   +2 more sources

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The Secrets of Barred Spiral Galaxies

Global Research Journal, 2022
Black holes start their lives as big dead stars in the depth of the universe. As they move towards the outer universe they gather cosmic dust, asteroids, planets, eventually they get bigger. The gravitational force increases and continues this process for billions of years. When an asteroid enters the gravitational field of an ever-growing dead star, it
openaire   +1 more source

Slow bars in spiral galaxies

Physics Letters A, 2000
Abstract Here we put forward some arguments in favour of the existence of slow bars. More then a half of spiral galaxies have in their central regions a bar — a structure in the form of triaxial ellipsoid. Historically two models of the bar were developed — those of the so called “slow” and “fast” bars. In both cases the bar is in some resonance with
A.M. Fridman, O.V. Khoruzhii
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The barred spiral structure of galaxies

Chinese Astronomy and Astrophysics, 1984
Abstract We have carried out a preliminary analysis of barred spirals using a gas-dynamical model. By means of the method of integral transform given in a previous paper [1], an analytical solution has been obtained which is in fair agreement with observations.
null Chen Zhen-cheng, null Weng Shi-da, null Xu Mei   +2 more
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DIFFUSION OF CHAOTIC ORBITS IN BARRED SPIRAL GALAXIES

International Journal of Bifurcation and Chaos, 2011
We study the diffusion of chaotic orbits in an N-body model simulating a barred spiral galaxy. Chaotic orbits with initial conditions outside corotation support the spiral structure of the galaxy due to the phenomenon of stickiness close and along the unstable asymptotic manifolds of the unstable periodic orbits.
M. Harsoula, C. Kalapotharakos, Georgios Contopoulos   +2 more
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STRUCTURES OUT OF CHAOS IN BARRED-SPIRAL GALAXIES

International Journal of Bifurcation and Chaos, 2012
We review the dynamical mechanisms we have found to support the morphological features in barred-spiral galaxies based on chaotic motions of stars in their gravitational fields. These morphological features are the spiral arms, that emerge out of the ends of the bar, but also shape the bar itself.
openaire   +1 more source

Barred Spirals and Formation of Spiral Arms by Galaxies

Nature, 1965
SO far the formation of spiral arms, especially regular arms, has not been satisfactorily explained. The investigation of this phenomenon can be facilitated by an analysis of similar, but more peculiar, objects—barred spirals. A characteristic barred galaxy has a straight bar, which at the ends transforms abruptly into spiral arms.
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On the theory of barred and magellanic spiral galaxies

Bulletin astronomique, 1968
We investigate the properties of stellar orbits in barred spiral galaxies to explain 1) the ring structures encircling the bars of SB(r) galaxies and 2) the unusual internal velocity field in the Magellanic barred Spiral NGC4027.
Freeman, Ken C., Harrington, R.
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Multiple patterns in spiral and barred galaxies

Publications of the Astronomical Society of the Pacific, 1993
Our ability to locate resonances of spiral patterns in galaxies is severely limited if spirals are short-lived and if many patterns co-exist in the same galaxy. Theoreticians are currently divided on the basic question of whether spiral patterns are long-lived, but I argue that multiple, short-lived pattersn are to be expected. Bars, on the other hadn,
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