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Two tails in NGC 3656, and the major merger origin of shell and minor axis dust lane ellipticals

Marc Balcells
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Abstract

I report on the discovery of two faint (~ 26.8 Rmag/arcsec^2) tidal tails around the shell elliptical NGC 3656 (Arp 155). This galaxy had previously been interpreted as a case of accretion, or minor merger. The two tidal tails are inconsistent with a minor merger, and point instead to a disk-disk major merger origin. NGC 3656 extends Toomre's merger sequence toward normal elliptical galaxies, and hints at a major merger origin for shells and minor-axis dust lanes. A dwarf galaxy lies at the tip of one of the tidal tails. A prominent shell, which shows sharp azymuthal color discontinuities, belongs to a rotating dynamical component of young stars which includes the inner dust lane.

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Marc Balcells. 1997-07-01. Two tails in NGC 3656, and the major merger origin of shell and minor axis dust lane ellipticals. https://doi.org/10.1086/310854

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