Cannibal Applet Controls Cannibal Home

Satellite Parameters:

  • Satellite Mass: The mass of the satellite galaxy as a percentage of the central galaxy's disk mass.
  • Satellite Radius: The radius of the satellite galaxy in kiloparsecs.
  • Start Button: Starts the simulation.
  • Pause Button: Pauses the simulation.
  • Stop Button: Stops the simulation.

Orbit Parameters:

  • Apogee Radius: The maximum radius (in kiloparsecs) that will be achieved by the satellite. Cannibal will begin the simulation with the satellite at apogee.
  • Perigee Radius: The minimum radius (in kiloparsecs) that would be achieved by the satellite if its orbit did not decay.
  • Inclination: The angle the satellite's orbit makes with the galactic plane at the ascending node (in degrees).

Sim Parameters:

  • Number of Stars: The number of stars in the satellite galaxy. Note that the simulation slows down greatly as more stars are added.
  • Timestep: The timestep to be used by Cannibal's RK4 integrator. This timestep is only used when the number of stars is greater than zero. For computing the propagation with zero stars, Cannibal uses an adaptive timestep, RK45 integrator.
  • Disk Effects Toggle: Toggle the effects of the galactic disk. Disabling disk effects will simulate the satellites propagation through a dark matter halo.
  • Mass Loss Toggle: Toggles the effects of mass loss in the satellite. When disabled, the satellite's mass will not deminish as it falls into the central galaxy.

Satellite View:

The satellite view provides a two-dimensional view of the satellite in the xy-plane. In the upper left corner of the window is the current tidal radius of the galaxy in kiloparsecs. The tidal radius is graphically indicated by the green circle about the center of the satellite.

  • Holding down the SHIFT key while dragging the mouse up and down will zoom the view in and out.

Galaxy View:

The galaxy view provides a three-dimensional view of the satellite's orbit about the central galaxy. At the center of the central galaxy are the Cartesian axes. The galactic disk is represented by the yellow circle in the xy-plane, and has a radius of 10,000 kpc. The center of the satellite galaxy is represented by a red ball. By using the Show Path Toggle you can enable or disable a green trace of the satellite's orbit. However, enabling this feature may slow the applet down.

  • Dragging the mouse in this window will move the viewpoint about the center of the galaxy.
  • Holding down the SHIFT key while dragging the mouse up and down will zoom the view in and out.