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Formation of Bi-Polar Spiral Features in Galactic Nuclei

Published online by Cambridge University Press:  07 August 2017

Paris Pişmiş
Affiliation:
Instituto de Astronomía, Universidad Nal. Autónoma de México, Apdo. Postal 70-264, México 04510, D.F.
Edmundo Moreno
Affiliation:
Instituto de Astronomía, Universidad Nal. Autónoma de México, Apdo. Postal 70-264, México 04510, D.F.

Extract

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In earlier communications we have called attention to the existence of very tight spiral formations in the nuclei of some galaxies, particularly of the early type barred spirals, proposing a mechanism for their formation (Pişmiş and Moreno 1984). These kiloparsec-scale structures are loosely termed “rings” but their overall morphology suggests strongly that the image is a tightly wound double spiral usually delineated by knots of emitting material, “hot-spots”. A striking characteristic of these spirals is their very high luminosity compared to the outer regions of the galaxy. 26 galaxies with “nuclear” spirals are listed by Buta, thesis. A systematic search with short exposure high resolution imagery may reveal many more nuclear spirals. NGC 4736 (Sb) though not a barred spiral has a well defined inner spiral delineated by very luminous H II regions.

Type
Part 8: Relationships of Nucleus, Galaxy and Environment
Copyright
Copyright © Kluwer 1989 

References

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