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An Experimental Study of Counter-Rotating Cores in Elliptical Galaxies

Published online by Cambridge University Press:  12 April 2016

R. H. Miller
Affiliation:
University of Chicago and Theoretical Studies Branch, NASA-Ames Research Center
G. R. Roelofs
Affiliation:
University of Chicago and Theoretical Studies Branch, NASA-Ames Research Center
B. F. Smith
Affiliation:
University of Chicago and Theoretical Studies Branch, NASA-Ames Research Center

Extract

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Recent observational studies (Franx and Illingworth 1987; Jedrzejewski and Schechter 1988; Bender 1988; Illingworth and Franx 1989) have shown that some elliptical galaxies have a small region near the center that rotates in the opposite direction from the outer parts of the galaxy. Often the rotation in the central part is much faster than that in the outer part. A few other galaxies show a small region near the center that rotates in the same di rection as the rest of the galaxy, but much faster. Either way, the part near the center that shows a strange pattern of rotation (the “core”) has been interpreted as a distinct dynamical subsystem. Very briefly, the observational data seem to be that (1) anomalies show up in rotation curves near the centers of some elliptical galaxies and that (2) galaxies with these strange rotational properties do not show a photometric signature: there are no noticeable bumps in the brightness profile and no unusual shapes of isophotal contours that would suggest an excess of matter concentrated near the center. No strong color variations have been reported. The puzzle is to learn what we can about elliptical galaxies in general, and about galaxies with strange central regions in particular, from these observational facts.

Type
VII. Classical Theory of Pairs
Copyright
Copyright © NASA 1990

References

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Jedrzejewski, R., and Schechter, P. L. 1988, Ap.J.(Letters) 330, L87, Fiche 104–F1.Google Scholar
Miller, R. H., and Smith, B. F. 1990a, “Off-Center Nuclei in Galaxies” (submitted).Google Scholar
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