2015/10/13 by Joshua E. Barnes, Barnes, Joshua E.
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysics of Galaxies (astro-ph.GA) #FOS: Physical sciences #Galaxies: Formation, Evolution, Phenomena #Stellar, planetary, and galactic studies #astro-ph.GA
paper · pdf · doi:10.48550/arxiv.1510.03653
MNRAS; accepted 2015 October 13, in original form 2015 May 05. 26 pages, 24 figures. A version with high-resolution figures is available at http://www.ifa.hawaii.edu/~barnes/research/galaxy_structure/tog3.pdf [8.2 Mb], and the supplemental figures are available at http://www.ifa.hawaii.edu/~barnes/research/galaxy_structure/tog3_sup.pdf [3.0 Mb]
arxiv created 2015/10/13 · openalex publication_date 2015/10/13 · arxiv updated 2015/10/14 · openalex created_date 2022/10/03 · openalex updated_date 2026/07/28
Tidal interactions between disc galaxies depend on galaxy structure, but the details of this relationship are incompletely understood. I have constructed a three-parameter grid of bulge/disc/halo models broadly consistent with ΛCDM, and simulated an extensive series of encounters using these models. Halo mass and extent strongly influence the dynamics of orbit evolution. In close encounters, the transfer of angular momentum mediated by the dynamical response of massive, extended haloes can reverse the direction of orbital motion of the central galaxies after their first passage. Tidal response is strongly correlated with the ratio ve / vc of escape to circular velocity within the participating discs. Moreover, the same ratio also correlates with the rate at which tidal tails are reaccreted by their galaxies of origin; consequently, merger remnants with `twin tails', such as NGC 7252, may prove hard to reproduce unless (ve / vc)2 \lesssim 5.5. The tidal morphology of an interacting system can provide useful constraints on progenitor structure. In particular, encounters in which halo dynamics reverses orbital motion exhibit a distinctive morphology which may be recognized observationally. Detailed models attempting to reproduce observations of interacting galaxies should explore the likely range of progenitor structures along with other encounter parameters.