Collision of Galaxies (Toomre simulation)
Joachim Köppen Kiel Feb. 2022
Galaxy One
number of particles
mass [1011 Msun]
radial scale [kpc]
rotation sense
inclination, axis PA [°]
initial X,Y,Z [kpc]
VXY,PA;VZ [km/s]
Galaxy Two
number of particles
mass [1011 Msun]
radial scale [kpc]
rotation sense
inclination, axis PA [°]
initial X,Y,Z [kpc]
VXY,PA;VZ [km/s]
comp.time step [Myr]
plot time step [Gyr]
time now [Gyr]
violet ... red:
Make the data cube (XP-YP-VP) by rotating the objects via:
tilt X
tilt Y
tilt Z
tilt X2
View (XPP-YPP) of the data cube after tilting it around its axes:
ZP
YP
XP
Some brief explanations
This computes the evolution of representative stars in the disk
of two spiral galaxies which collide with each other.
X,Y,Z, VX,VY,VZ are the positions and velocities in true space.
XP,ZP,VP are the coordinates in the data cube, produced by
projection via inclination and p.a.rotation angles.
XPP,YPP are coordinates in a 2-D view of the data cube,
as defined by the tilt angles about YPP and ZPP axes.
The ZPP axis is normal to the image plane.
start a new model: after entering the various model parameters
press the start button.
run a model: click the button with the right arrow to make
one time step. Keep pressing this button to continuously step
forward.
run a model backwards: click the button with the left arrow.
This will work allright, except for stars of one galaxy crossing the
centre of the other. In the interest of a fast display, trajectories
of these stars are not followed accurately, thus they are only
kicked out at high speed...