NGC 4038/4039 are perhaps the most famous pair of nearby interacting
galaxies known for their symmetrically placed tidal tails resembling insect
antennae. N-body simulations of the formation of the Antennae's tidal tails
allow us to set limits on the total amount of dark matter in the interacting
galaxies. Shown below are two simulations using different amounts of dark
matter in the galaxy models. The low mass model only contains 4 times as
much mass in dark matter as stars while the high mass model contains 30
times as much dark matter. The low mass model easily produces long tidal
tails like the real pair while the high mass model fails, producing only
short, stubby features. Simulations using intermediate masses show that
long tails only arise when the mass of dark matter is less than 10 times
the mass of the stars.
Live Antennae
Here are two animations of the collision of the low mass model galaxies
- one from a view in the plane of the sky and one looking down onto the
orbital plane of the collision. The simulation spans about 2 billion years.
Click to see the movie of the interaction from the observer's point
of view.
Click to see the movie of the interaction in the orbital plane
John Dubinski