Results are presented from a grid of simulations of collisions between two model galaxies, each consisting of a rigid halo potential a gas disk. The disks are modeled in three-dimensions with an SPH algorithm using either an isothermal equation of state or an adiabatic one with terms for cooling and heating from young star activity. The large-scale wave and tidal structures are very similar with either equation of state, but there are important differences, which in some cases result from the different jump conditions across the high-velocity shocks. Substantial bridges form in all cases, as observed in VIIZw466 and the Cartwheel galaxies, except in a comparison run with a diskless companion. The bridge can consist of gas originating primarily from either companion, depending on the orientation of the companion disk at impact. In most cases the smaller companion disk is disrupted by the impact, but reforms via accretion from the bridge.
American Astronomical Society Meeting Abstracts #188
- Pub Date:
- May 1996