Flocculent and grand design spiral galaxies in groups - Time scales for the persistence of grand design spiral structures

1983 ◽  
Vol 267 ◽  
pp. 31 ◽  
Author(s):  
B. G. Elmegreen ◽  
D. M. Elmegreen
Keyword(s):  
Time Scales ◽  
Spiral Galaxies ◽  
Grand Design ◽  
Spiral Structures ◽  
Design Spiral

Observational Manifestation of Chaos in Grand Design Spiral Galaxies

2003 ◽  
pp. 223-234 ◽  
Author(s):  
Alexei M. Fridman ◽  
Roald Z. Sagdeev ◽  
Oleg V. Khoruzii ◽  
Evgenii V. Polyachenko
Keyword(s):  
Spiral Galaxies ◽  
Grand Design ◽  
Observational Manifestation ◽  
Design Spiral

scholarly journals Outer spiral structure in disk galaxies

2016 ◽  
Vol 11 (S321) ◽  
pp. 123-123
Author(s):  
P.A. Patsis
Keyword(s):  
Periodic Orbits ◽  
Spiral Galaxies ◽  
Spiral Structure ◽  
Disk Galaxies ◽  
Spiral Arms ◽  
Chaotic Orbits ◽  
Grand Design ◽  
Pattern Speed ◽  
Spiral Structures ◽  
Barred Spiral Galaxies

AbstractIn several grand design barred-spiral galaxies it is observed a second, fainter, outer set of spiral arms. Typical examples of objects of this morphology can be considered NGC 1566 and NGC 5248. I suggest that such an overall structure can be the result of two dynamical mechanisms acting in the disc. The bar and both spiral systems rotate with the same pattern speed. The inner spiral is reinforced by regular orbits trapped around the stable, elliptical, periodic orbits of the central family, while the outer system of spiral arms is supported by chaotic orbits. Chaotic orbits are also responsible for a rhomboidal area surrounding the inner barred-spiral region. In general there is a discontinuity between the two spiral structures at the corotation region.

scholarly journals Analysis of Resonances in Grand Design Spiral Galaxies

2001 ◽  
Vol 547 (1) ◽  
pp. 187-199 ◽  
Author(s):  
Nelson Vera‐Villamizar ◽  
Horacio Dottori ◽  
Ivanio Puerari ◽  
Reinaldo de Carvalho
Keyword(s):  
Spiral Galaxies ◽  
Grand Design ◽  
Design Spiral

scholarly journals Galactic spiral generation in tidal encounters

2015 ◽  
Vol 11 (S315) ◽  
Author(s):  
Alex R. Pettitt ◽  
Elizabeth J. Tasker ◽  
James W. Wadsley
Keyword(s):  
Spiral Galaxies ◽  
Key Points ◽  
The Galaxy ◽  
Grand Design ◽  
Spiral Structures ◽  
Galactic Spiral ◽  
Morphological Differences ◽  
The Universe ◽  
Disc Galaxies ◽  
Real Universe

AbstractThe existence of grand design spiral galaxies in the universe is still a standing problem. The passage of a small companion is known to be able to induce spiral structures in disc galaxies, but there remains questions over how relevant this mechanism is to the galaxies observed in the real universe. Our study aims to address two key points regarding such interactions; the limiting mass companion needed to drive tidal spiral structures, and the differences between the resulting gas and stellar morphology. We find the minimum mass of a companion to be as low as 5% of the stellar mass of the galaxy, and that the arms formed in the gas and the stars display very minor dynamical and morphological differences.

Evidence for small halos in grand design spiral galaxies

1990 ◽  
Vol 364 ◽  
pp. 412 ◽  
Author(s):  
Debra Meloy Elmegreen ◽  
Bruce G. Elmegreen
Keyword(s):  
Spiral Galaxies ◽  
Grand Design ◽  
Design Spiral

scholarly journals Stellar Spirals in Triaxial Dark Matter Halos

2016 ◽  
Vol 11 (S321) ◽  
pp. 120-120
Author(s):  
Shaoran Hu ◽  
Debora Sijacki
Keyword(s):  
Dark Matter ◽  
Dark Matter Halo ◽  
Dark Matter Halos ◽  
Grand Design ◽  
Spiral Structures ◽  
Design Spiral

AbstractTwo-armed grand-design spirals may form if the shape of its dark matter halo changes abruptly enough. The feasibility of such a mechanism is tested in realistic simulations. The interplay of such externally-driven spirals and self-induced transient spirals is then studied. Subhaloes are also found to lead to transient grand-design spiral structures when they impact the disk.

scholarly journals Young stellar clusters triggered by a density wave in NGC 2997

2006 ◽  
Vol 2 (S237) ◽  
pp. 417-417
Author(s):  
P. Grosbøl ◽  
H. Dottori ◽  
R. Gredel
Keyword(s):  
Large Scale ◽  
Near Infrared ◽  
Density Wave ◽  
Star Formation History ◽  
Stellar Clusters ◽  
Star Forming ◽  
Continuous Formation ◽  
Grand Design ◽  
K Band ◽  
Design Spiral

AbstractBright knots along the arms of grand-design spiral galaxies are frequently seen on near-infrared K-band images. To investigate their nature, low resolution K-band spectra of a string of knots in the southern arm of the grand design, spiral galaxy NGC 2997 were obtained with ISAAC/VLT. Most of the knots show strong Brγ emission while some have H2 and HeI emission. A few knots show indications of CO absorption. Their spectra and absolute K magnitudes exceeding -12 mag suggest them to be very compact, young stellar clusters with masses up to 5 × 104 M. The knots' azimuthal distance from the K-band spiral correlates well with their Brγ strength, indicating that they are located inside the co-rotation of the density wave, which triggered them through a large-scale, star-forming front. These relative azimuthal distances suggest an age spread of more than 1.6 Myr, which is incompatible with standard models for an instantaneous star burst. This indicates a more complex star-formation history, such as several bursts or continuous formation.

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