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Paper: Perturbation of Dark Halos and Elliptical Galaxies During Flyby Encounters
Volume: 230, Galaxy Disks and Disk Galaxies
Page: 457
Authors: Vesperini, E.; Weinberg, M. D.
Abstract: We study the structure produced in dark halos and in elliptical galaxies during an unbound encounter. We show that relatively weak encounters with low-mass interloping galaxies can cause observable distortions in the primaries. The resulting asymmetries may persist long after the interloper is evident. Any distortion produced in a dark halo can distort an embedded stellar disk, possibly leading to the formation of lopsided and warped disks. We study the distribution of the A parameter defined by Abraham et al. (sensitive to lopsidedness) and show that this is in good agreement with the range spanned by observed values for local galaxies and for distant galaxies in the Medium Deep Survey and in the Hubble Deep Field. We propose a generalized asymmetry parameter, A(r), which provides a detailed information on the radial structure of the asymmetry produced by the mechanism explored here.
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