Table 3: Parameters used for the best model.
  Model units* Phys. units
NW model parameters
Number of particles in stellar disk 8192  
Disk total mass 0.54 $3.02 \times10^{10} ~ {M}_\odot$
Disk radial scale length 0.7 2.45 kpc
Disk vertical scale thickness 0.07 0.245 kpc
Reference radius $R_{\rm ref}$ 1.3 4.55 kpc
Toomre Q at $R_{\rm ref}$ 1.4  
Number of particles in gas disk 8192  
Gas disk total mass 0.054 $3.02 \times10^9 ~ {M}_\odot$
Gas disk radial scale length 1.05 3.675 kpc
Gas disk vertical scale thickness 0.021 0.0735 kpc
Toomre Q at $R_{\rm ref}$ 1.1  
Number of particles in bulge 1024  
Bulge total mass 0.054 $3.02 \times10^9 ~ {M}_\odot$
Bulge radial scale length 0.14 0.49 kpc
Number of particles in halo 8192  
Halo mass 2.04 $1.14 \times10^{11} ~ {M}_\odot$
Halo cutoff radius 7.0 24.5 kpc
Halo core radius 0.7 2.45 kpc
SE model parameters
Number of particles in stellar disk 8192  
Disk total mass 0.23 $1.28 \times10^{10} ~ {M}_\odot$
Disk radial scale length 0.6 2.1 kpc
Disk vertical scale thickness 0.06 0.21 kpc
Reference radius $R_{\rm ref}$ 1.5 5.25 kpc
Toomre Q at $R_{\rm ref}$ 1.4  
Number of particles in gas disk 8192  
Gas disk total mass 0.023 $1.28 \times10^{9} ~ {M}_\odot$
Gas disk radial scale length 0.9 3.15 kpc
Gas disk vertical scale thickness 0.004 0.014 kpc
Toomre Q at $R_{\rm ref}$ 1.1  
Number of particles in bulge 1024  
Bulge total mass 0.046 $2.57 \times10^{9} ~ {M}_\odot$
Bulge radialscale length 0.12 0.42 kpc
Number of particles in halo 8192  
Halo mass 0.86 $4.80 \times10^{10} ~ {M}_\odot$
Halo cutoff radius 5.7 19.95 kpc
Halo core radius 0.57 1.995 kpc
Encounter parameters from our best model
Pericenter distance 2.0 7.0 kpc
Present distance 2.4 8.4 kpc
Pericenter vector direction** (-0.933, 0.357, 0.0473)  
Orbital plane normal vector direction*** (0.067, 0.0432, 0.997)  
Initial galaxy separation 12.6 44.1 kpc
Notes: * Simulations were done in a system of units with G=1. Model units scale to physical ones such that length unit is 3.5 kpc, unit velocity 262 km s-1, unit mass  $5.586 \times 10^{10} ~ {M}_\odot$, and unit time 13.062 Myr. ** Vector components defined in a Cartesian reference frame (X, Y, Z), with X to the North, Y to the West, and Z in the line of sight direction, with positive values towards the observer. *** The orbital plane's normal vector is the direction of the orbital angular momentum (reference frame defined as in *).

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